To 


i 


THE 

FAIRY-LAND  OF  SCIENCE. 


Fig.  29. 


Glacier  carrying  down  Stones.    Seep.  119- 


THE 


Fairy-land  of  Science. 


UY 

ARABELLA  B.  BUCKLEY, 

AUTHOR  OF  *A  SHORT   HISTORY  OF  NATURAL  SCIENCE, 
'  BOTANICAL  TARLi:S  FOR  YOUNG  STUDENTS,'  RTC 


ILLUSTRATED. 


"  for  they  remember  yet  the  taies  we  told  tlu-iu 
Aroutid  the  hearth,  of  fairies,  long  ago, 
Wlien  they  \o\ed  still  in  f.uicy  to  betiuld  them 
Quick  dancing  earthward  in  the  featheiy  sudw. 

But  now  the  young  and  fresh  unaginatton 
Finds  traces  ol  their  |)re>ence  everywhere. 

And  peop]e<i  with  a  new  and  bright  creation 
Tiit^  iit*.ar  lihit*  r{utiiii>er>-  t»l  lite  siiuuy  air.*' 


NEW  YORK: 

D.    APPLETON   AND  COMPANY, 
I,   3,   AND   s   BOND  STREET. 
1893. 


PREFACE. 


The  Ten  Lectures  of  which  this  volume  is  composed 
were  delivered  last  spring,  in  St.  John*s  Wood,  to  a 
large  audience  of  children  and  their  friends,  and  at 
their  conclusion  I  was  asked  by  many  of  those  present 
to  publish  them  for  a  child's  reading  book. 

At  first  I  hesitated,  feeling  that  written  words  can 
never  produce  the  same  effect  as  viva-voce  delivery. 
But  the  majority  of  my  juvenile  hearers  were  evi- 
dently so  deeply  interested  that  I  am  encouraged  to 
think  that  the  present  work  may  be  a  source  of 
pleasure  to  a  wider  circle  of  young  people,  and  at  the 
same  time  awaken  in  them  a  love  of  nature  and  of 
the  study  of  science. 

The  Lectures  have  been  entirely  rewritten  from 
the  short  notes  used  when  they  were  delivered. 
With  the  exception  of  the  first  of  the  series,  none  of 
them  have  any  pretensions  to  originality,  their  object 
being  merely  to  explain  well-known  natural  facts  in 
simple  and  pleasant  language.  Throughout  the  whole 
book  I  have  availed  myself  freely  of  the  leading 
popular  works  on  science,  but  have  found  it  im- 
possible to  give  special  references,  as  nearly  all  the 


PRE  FACE. 


matter  I  have  dealt  with  has  long  been  the  common 
property  of  scientific  teachers. 

I  am  much  indebted  to  Mr.  J.  Cooper  for  the  zeal 
and  assiduity  he  has  shown  in  carrying  out  my  sug- 
gestions for  illustrations.  All  the  engravings,  with 
one  exception,  were  executed  under  his  superinten- 
dence. 

Arabella  H.  Buckley. 


ChrutrntiSy  187b. 


TABLE  OF  CONTENTS. 


LECTURE  I. 
The  Fairy-land  of  Science:  how  to  entkk  it;  how  to 


USE  IT  ;  AND  now  TO  ENjOY  IT  -  1 

LECTURE  IL 
Sunbeams,  and  the  Work  they  do   ,  26 

LECTURE  IIL 
The  Aerial  Ocean  in  witicii  we  live   50 

LECTURE  IV. 
A  Drop  of  Water  on  its  Travels       ..     ,   73 

LECTURE  V. 
The  Two  grkat  Sculptors — Water  and  Ice  99 


LECTURE  VL 
The  Voices  of  Nature,  and  how  we  hear  them        ..  124 


viii  TABLE  OF  CONTENTS. 

LECTURE  VII. 
The  Life  of  a  Primrose  r.  «•  «•    ..  150 

LECTURE  VIIL 
The  History  of  a  Piece  of  Coal  171 

LECTURE  TX. 
Bees  in  the  Hive   193 

LECTURE  X. 
Bees  and  Flowers    »,    «.  112 


THE 

FAIRY-LAND  OF  SCIENCE. 


LECTURE  I. 

HOW  TO  ENTER  IT  ;    HOW  TO  USE  IT  ;   AND  HOW 

TO  ENJOY  IT. 


probably  look  upon  science  as  a  bundle  of  dry  facts, 
while  fairy-land  is  all  that  is  beautiful  and  full  of 


2  THE  FAIRY-LAND  OF  SCIENCE, 


poetry  and  imagination.  But  I  thoroughly  believe 
myself,  and  hope  to  prove  to  you,  that  science  is  full 
of  beautiful  pictures,  of  real  poetry,  and  of  wonder- 
working fairies ;  and  what  is  more,  I  promise  you 
they  shall  be  true  fairies,  whom  you  will  love  just 
as  much  when  you  are  old  and  greyheaded  as  when 
you  are  young ;  for  you  will  be  able  to  call  them 
up  wherever  you  wander  by  land  or  by  sea,  through 
meadow  or  through  wood,  through  water  or  through 
air;  and  though  they  themselves  will  always  remain 
invisible,  yet  you  will  see  their  wonderful  power  at 
work  everywhere  around  you. 

Let  us  first  see  for  a  moment  what  kind  of  tales 
science  has  to  tell,  and  how  far  they  are  equal  to  the 
old  fairy  tales  we  all  know  so  well.  Who  does  not 
remember  the  tale  of  the  *'  Sleeping  Beauty  in  the 
Wood/*  and  how  under  the  spell  of  the  angry  fairy 
the  maiden  pricked  herself  with  the  spindle  and  slept 
a  hundred  years  ?  How  the  horses  in  the  stall,  the 
dogs  in  the  court-yard,  the  doves  on  the  roof,  the  cook 
who  was  boxing  the  scullery  boy's  ears  in  the  kitchen, 
and  the  king  and  queen  with  all  their  courtiers  in  the 
hall  remained  spell -bound,  while  a  thick  hedge  grew 
up  all  round  the  castle  and  all  within  was  still  as 
death.  But  when  the  hundred  years  had  passed  the 
valiant  prince  came,  the  thorny  hedge  opened  before 
him  bearing  beautiful  flowers  ;  and  he,  entering  the 
castle,  reached  the  room  where  the  princess  lay,  and 
with  one  sweet  kiss  raised  her  and  all  around  her  to 
life  again. 

Can  science  bring  any  tale  to  match  this  } 

Tell  me,  is  there  anything  in  this  world  more  busy 


fHE  FAIRY-LAND  OF  SCIENCE.  3 


and  active  than  water,  as  it  rushes  along  in  the  swift 
brook,  or  dashes  over  the  stones,  or  spouts  up  in  the 
fountain,  or  trickles  down  from  the  roof,  or  shakes 
itself  into  ripples  on  the  surface  of  the  pond  as  the 
A^ind  blows  over  it  ?  But  have  you  never  seen  this 
water  spell-bound  and  motionless  ?  Look  out  of  the 
window  some  cold  frosty  morning  in  winter,  at  the 
little  brook  which  yesterday  was  flowing  gently  past 
the  house,  and  see  how  still  it  lies,  with  the  stones 
over  which  it  was  dashing  now  held  tightly  in  its  icy 
grasp.  Notice  the  wind-ripples  on  the  pond  ;  they 
have  become  fixed  and  motionless.  Look  up  at  the 
roof  of  the  house.  There,  instead  of  living  doves 
merely  charmed  to  sleep,  we  have  running  water 
caught  in  the  very  act  of  falling  and  turned  into 
transparent  icicles,  decorating  the  eaves  with  a  beau- 
tiful crystal  fringe.  On  every  tree  and  bush  you  will 
catch  the  water-drops  napping,  in  the  form  of  tiny 
crystals ;  while  the  fountain  looks  like  a  tree  of  glass 
with  long  down-hanging  pointed  leaves.  Even  the 
damp  of  your  own  breath  lies  rigid  and  still  on  the 
window-pane  frozen  into  delicate  patterns  like  fern- 
leaves  of  ice. 

All  this  water  was  yesterday  flowing  busily,  or 
falling  drop  by  drop,  or  floating  invisibly  in  the  air  ; 
now  it  is  all  caught  and  spell-bound — by  whom  1 
By  the  enchantments  of  the  frost-giant  who  holds  it 
fast  in  his  grip  and  will  not  let  it  go. 

But  wait  awhile,  the  deliverer  is  coming.  In  a 
few  weeks  or  days,  or  it  may  be  in  a  few  hours, 
the  brave  sun  will  shine  down  ;  the  dull-grey,  leaden 
sky  will  melt  before  him,  as  the  hedge  gave  way 


^  THE  FAIRY  LAND  OF  SCIENCE. 

before  the  prince  in  the  fairy  tale,  and  when  the  sun- 
beam gently  kisses  the  frozen  water  it  will  be  set 
free.  Then  the  brook  will  flow  rippling  on  again  ; 
the  frost-drops  will  be  shaken  down  from  the  trees, 
the  icicles  fall  from  the  roof,  the  moisture  trickle 
down  the  window-pane,  and  in  the  bright,  warm  sun- 
shine all  will  be  alive  again. 

Is  not  this  a  fairy  tale  of  nature  \  and  such  as  these 
it  is  which  science  tells. 

Again,  who  has  not  heard  of  Catskin,  who  came 
out  of  a  hollow  tree,  bringing  a  walnut  containing 
three  beautiful  dresses — the  first  glowing  as  the  sun, 
the  second  pale  and  beautiful  as  the  moon,  the  third 
spangled  like  the  star-lit  sky,  and  each  so  fine  and 
delicate  that  all  three  could  be  packed  in  a  nut  ?  But 
science  can  tell  of  shells  so  tiny  that  a  whole  group 
of  them  will  lie  on  the  point  of  a  pin,  and  many 
thousands  be  packed  into  a  walnut  shell ;  and  each 
one  of  these  tiny  structures  is  not  the  mere  dress  but 
the  home  of  a  living  animal.  It  is  a  tiny,  tiny  shell- 
palace  made  of  the  most  delicate  lacework,  each  pat- 
tern being  more  beautiful  than  the  last ;  and  what  is 
more,  the  minute  creature  that  lives  in  it  has  built  it 
out  of  the  foam  of  the  sea,  though  he  himself  is 
nothing  more  than  a  drop  of  jelly. 

Lastly,  anyone  who  has  read  the  *  Wonderful  Tra- 
vellers'  must  recollect  the  man  whose  sight  was  so 
keen  that  he  could  hit  the  eye  of  a  fly  sitting  on  a 
tree  two  miles  away.  But  tell  me,  can  you  sec 
gas  before  it  is  lighted,  even  when  it  is  coming 
out  of  the  gas-jet  close  to  your  eyes }  Yet,  if  you 
learn  to  use  that  wonderful  instrument  the  spectre- 


THE  FAIRY-LAND  OF  SCIENCE.  5 


scope,  it  will  enable  you  to  tell  one  kind  of  gas 
from^  another,  even  when  they  are  both  ninety-one 
millions  of  miles  away  on  the  face  of  the  sun  ;  nay 
more,  it  will  read  for  you  the  nature  of  the  different 
gases  in  the  far  distant  stars,  billions  of  miles  away, 
and  actually  tell  you  whether  you  could  find  there  any 
of  the  same  metals  which  we  have  on  the  earth. 

We  might  find  hundreds  of  such  fairy  tales  in  the 
domain  of  science,  but  these  three  will  serve  as  ex- 
amples, and  we  must  pass  on  to  make  the  acquaint- 
ance of  the  science-fairies  themselves,  and  see  if  they 
are  as  real  as  our  old  friends. 

Tell  me,  why  do  you  love  fairy-land  ?  what  is  its 
charm  ?  Is  it  not  that  things  happen  so  suddenly, 
so  mysteriously,  and  without  man  having  anything  to 
do  with  it }  In  fairy-land,  flowers  blow,  houses  spring 
up  like  Aladdin's  palace  in  a  single  night,  and  people 
are  carried  hundreds  of  miles  in  an  instant  by  the 
touch  of  a  fairy  wand. 

And  then  this  land  is  not  some  distant  country 
to  which  we  can  never  hope  to  travel.  It  is  here 
in  the  midst  of  us,  only  our  eyes  must  be  opened  or 
we  cannot  see  it.  Ariel  and  Puck  did  not  live  in 
some  unknown  region.  On  the  contrary,  Ariel's 
song  is 

Where  tlie  hee  sucks,  there  siick  I ; 
In  a  cowslip's  bell  I  lie  ; 
There  I  couch  when  owls  do  cry. 
On  the  bat*s  back  I  do  fly. 
After  summer,  merrily." 

Tlie  peasant  falls  asleep  some  evening  in  a  v/ood, 
and  his  eyes  are  opened  by  a  fairy  wand,  so  thai  he 


6 


THE  FAIRY-LAND  OF  SCIENCE. 


sees  the  little  goblins  and  imps  dancing  round  him  on 
the  green  sward,  sitting  on  mushrooms,  or  in  the 
heads  of  the  flowers,  drinking  out  of  acorn-cups, 
fighting  with  blades  of  grass,  and  riding  on  grass- 
hoppers. 

So,  too,  the  gallant  knight,  riding  to  save  some  poo! 
oppressed  maiden,  dashes  across  the  foaming  torrer.t  ; 
and  just  in  the  middle,  as  he  is  being  swept  away, 
his  eyes  are  opened,  and  he  sees  fairy  water-nymphs 
soothing  his  terrified  horse  and  guiding  him  gently  to 
the  opposite  shore.  They  are  close  at  hand,  these 
sprites,  to  the  simple  peasant  or  the  gallant  knight,  or 
to  anyone  who  has  the  gift  of  the  fairies  and  can  see 
them.  But  the  man  who  scofTs  at  them,  and  does  not 
believe  in  them  or  care  for  them,  he  never  sees  them. 
Only  now  and  then  they  play  him  an  ugly  trick, 
leading  him  into  some  treacherous  bog  and  leaving 
him  to  get  out  as  he  may. 

Now,  exactly  all  this  which  is  true  of  the  faiiies  of 
our  childhood  is  true  too  of.  the  fairies  of  science. 
There  are  forces  around  us,  and  among  us,  which  I 
shall  ask  you  to  allow  me  to  call  fairies,  and  these  are 
ten  thousand  times  more  wonderful,  more  magical, 
and  more  beautiful  in  their  work,  than  those  of  the  old 
fairy  tales.  They,  too,  are  invisible,  and  many  people 
live  and  die  without  ever  seeing  them  or  caring  to  see 
them.  These  people  go  about  with  their  eyes  shut, 
either  because  they  will  not  open  them,  or  because  no 
one  has  taught  them  how  to  see.  They  fret  and  worry 
over  their  own  little  work  and  their  own  petty  troubles, 
and  do  not  know  how  to  rest  and  refresh  themselves, 
by  letting  the  fairies  open  their  eyes  and  shoiv  them 


THE  FAIRY-LAND  OF  SCIENCE. 


7 


the  calm  sweet  pictures  of  nature.  They  are  like 
Peter  Bell  of  whom  Wordsworth  wrote  : — 

**  A  primrose  by  a  river's  brim 
A  yellow  primrose  was  to  him, 
And  it  was  nothing  more." 

Bat  we  will  not  be  like  these,  we  will  open  our 
eyes,  and  ask,  "  What  are  these  forces  or  fciiries,  and 
how  can  we  see  them  } " 

Just  go  out  into  the  country,  and  sit  down  quietly 
and  watch  nature  at  work.  Listen  to  the  wind  as 
it  blows,  look  at  the  clouds  roiling  overhead,  and  the 
waves  rippling  on  the  pond  at  your  feet.  Hearken 
to  the  brook  as  it  flows  by,  watch  the  flower-buds 
opening  one  by  one,  and  then  ask  yourself,  How 
all  this  is  done  'i "  Go  out  in  the  evening  and  see 
the  dew  gather  drop  by  drop  upon  the  grass,  or 
trace  the  delicate  hoar-frost  crystals  which  bespangle 
every  blade  on  a  winters  morning.  Look  at  the 
•vivid  flashes  of  lightning  in  a  storm,  and  listen  to  the 
pealing  thunder:  and  then  tell  me,  by  what  machinery 
is  all  this  wonderful  work  done  }  Man  does  none  of 
it,  neither  could  he  stop  it  if  he  were  to  try  ;  for  it 
is  all  the  work  of  those  invisible  forces  or  fairies 
whose  acquaintance  I  wish  you  to  make.  Day  and 
night,  summer  and  winter,  storm  or  calm,  these  fairies 
are  at  w^ork,  and  we  may  hear  them  and  know  them, 
and  make  friends  of  them  if  w^e  will. 

There  is  only  one  gift  we  must  have  before  we  can 
learn  l:o  know  them  —we  must  have  iiuaginatioii.  I 
d  )  not  mean  mere  fancy,  which  creates  unreal  images 
and  impossible  monsters,  but  imagination,  the  power 
of  making  pictures  or  images  in  our  mind,  of  that 
which  is,  though  it  is  invisible  to  us.    Most  children 


s 


THE  FAFRY-LAND  OF  SCIENCE, 


have  this  glorious  gift,  and  love  to  picture  to  them- 
selves all  that  is  told  them,  and  to  hear  the  same  tale 
over  and  over  again  till  they  see  every  bit  of  it  as  -f  it 
were  real.  This  is  why  they  are  sure  to  love  science 
if  its  tales  are  told  them  aright ;  and  I,  for  one,  hope 
the  day  may  never  come  when  we  may  lose  that 
childish  clearness  of  vision,  which  enables  us  through 
the  temporal  things  which  are  seen,  to  realize  those 
eternal  truths  which  are  unseen. 

If  you  have  this  gift  of  imagination  come  with  me, 
and  in  these  lectures  we  will  look  for  the  invisible 
fairies  of  nature. 

Watch  a  shower  of  rain.  Where  do  the  drops  come 
from  }  and  why  are  they  round,  or  rather  slightly 
oval  ?  In  our  fourth  lecture  we  shall  see  that  the 
little  particles  of  water  of  which  the  rain- drops  are 
made,  were  held  apart  and  invisible  in  the  air  by  heat, 
one  of  the  most  wonderful  of  our  forces*  or  fairies, 
till  the  cold  wind  passed  by  and  chilled  the  air.  Then, 
when  there  was  no  longer  so  much  heat,  another 
invisible  force,  coliesion^  which  is  always  ready  and 
waiting,  seized  on  the  tiny  particles  at  once,  and 
locked  them  together  in  a  drop,  the  closest  form  in 
which  they  could  lie.  Then  as  the  drops  became 
larger  and  larger  they  fell  into  the  grasp  of  another 
invisible  force,  gravitation,  which  dragged  them  down 
to  the  earth,  drop  by  drop,  till  they  made  a  shower  of 

*  I  am  quite  aware  of  the  danger  incurred  by  using  this  word  "  force,* 
especially  in  the  plural ;  and  how  even  the  most  modest  little  book  may 
suffer  at  the  hands  of  scientific  purists  by  employing  it  rashly.  As, 
however,  the  better  term  "energy**  would  not  serve  here,  I  hope  1  may 
be  forgiven  for  retaining  the  much-abused  term,  especially  as  1  sin  la 
Tery  good  company. 


THE  FAIRY-LAND  OF  SCIENCE. 


9 


rain.  Pause  for  a  moment  and  think.  You  have 
surely  heard  of  gravitation,  by  which  the  sun  holds 
the  earth  and  the  planets,  and  keeps  them  moving 
round  him  in  regular  order  ?  Well,  it  is  this  same 
gravitation  which  is  at  work  also  whenever  a  shower 
of  rain  falls  to  the  earth.  Who  can  say  that  he  is  not 
a  great  invisible  giant,  always  silently  and  invisibly 
toiling  in  great  things  and  small  whether  we  wake  or 
sleep 

Now  the  shower  is  over,  the  sun  comes  out,  and  the 
ground  is  soon  as  dry  as  though  no  rain  had  fallen. 
Tell  me,  what  has  become  of  the  rain-drops  ?  Part  no 
doubt  have  sunk  into  the  ground,  and  as  for  the  rest, 
why  you  will  say  the  sun  has  dried  them  up.  Yes, 
but  how  ?  The  sun  is  more  than  ninety-one  millions 
of  miles  away ;  how  has  he  touched  the  rain-drops  ? 
Have  you  ever  heard  that  invisible  waves  are  travelling 
every  second  over  the  space  between  the  sun  and  us  } 
We  shall  see  in  the  next  lecture  how  these  waves  are 
the  sun's  messengers  to  the  earth,  and  how  they  tear 
asunder  the  rain-drops  on  the  ground,  scattering  them 
in  tiny  particles  too  small  for  us  to  see,  and  bearing 
them  away  to  the  clouds.  Here  are  more  invisible 
fairies  working  every  moment  around  you,  and  you 
cannot  even  look  out  of  the  window  witliout  seeing 
the  work  they  are  doing. 

If,  however,  the  day  is  cold  and  frosty,  the  water 
dees  not  fall  in  a  shower  of  rain ;  it  comes  down  in  the 
shape  of  noiseless  snow.  Go  out  after  such  a  snow- 
shower,  on  a  calm  day,  and  look  at  some  of  the  flakes 
which  have  fallen  ;  you  will  see,  if  you  choose  good 
specimens,  that  they  are  not  mere  masses  of  frozen 

2 


THE  FAIRY'LAND  OF  SCIENCE, 


water,  but  that  each  one  is  a  beautiful  six-pointed 
crystal  star.  How  have  these  crystals  been  built  up  ? 
What  power  has  been  at  work  arranging  their  delicate 
forms  ?  In  the  fourth  lecture  we  shall  see  that  up  in 
the  clouds  another  of  our  invisible  fairies,  which,  for 
want  of  a  better  name,  we  call  the  force  of  crystal- 
lization," has  caught  hold  of  the  tiny  particles  of 
water  before  "  cohesion  had  made  them  into  round 
drops,  and  there  silently  but  rapidly,  has.  moulded 
them  into  those  delicate  crystal  stars  known  as  "  snow- 
flakes." 

And  now,  suppose  that  this  snow-shower  has  fallen 
early  in  February  ;  turn  aside  for  a  moment  from 
examining  the  flakes,  and  clear  the  newly-fallen  snow 
from  off"  the  flower-bed  on  the  lawn.  What  is  this 
little  green  tip  peeping  up  out  of  the  ground  under 
the  snowy  covering  ?  It  is  a  young  snowdrop  plant. 
Can  you  tell  me  why  it  grows  }  where  it  finds  its  food? 
what  makes  it  spread  out  its  leaves  and  add  to  its 
stalk  day  by  day  ?    What  fairies  are  at  work  here  ? 

First  there  is  the  hidden  fairy  "  life,"  and  of  her 
even  our  wisest  men  know  but  little.  But  they  know 
something  of  her  way  of  working,  and  in  Lecture  VII. 
we  shall  learn  how  the  invisible  fairy  sunbeams  have 
been  busy  here  also  ;  how  last  year's  snowdrop  plant 
caught  them  and  stored  them  up  in  its  bulb,  and  how 
now  in  the  spring,  as  soon  as  warmth  and  moisture 
creep  down  into  the  earth,  these  little  imprisoned  sun- 
waves  begin  to  be  active,  stirring  up  the  matter  in 
the  bulb,  and  making  it  swell  and  burst  upwards  till 
it  sends  out  a  little  shoot  through  the  surface  of  the 
soil.    Then  the  sun-waves  above-ground  take  up  the 


THE  FAIRY-LAND  OF  SCIENCE.  U 


work,  and  form  green  granules  in  the  tiny  leaves, 
helping  them  to  take  food  out  of  the  air,  while  the 
little  rootlets  below  are  drinking  water  out  of  the 
ground.  The  invisible  life  and  invisible  sunbeams  are 
busy  here,  setting  actively  to  work  another  fairy,  the 
force  of  "chemical  attraction,"  and  so  the  little  snow- 
drop plant  grows  and  blossoms,  without  any  help  from 
you  or  me. 

One  picture  more,  and  then  I  hope  you  will  believe 
in  my  fairies.  From  the  cold  garden,  you  run  into  the 
house,  and  find  the  fire  laid  indeed  in  the  grate,  but 
the  wood  dead  and  the  coals  black,  waiting  to  be 
lighted.  You  strike  a  match,  and  soon  there  is  a 
blazing  fire.  Where  does  the  heat  come  from  }  Why 
do  the  coals  burn  and  give  out  a  glowing  light  ?  Have 
you  not  read  of  gnomes  buried  down  deep  in  the  earth, 
in  mines,  and  held  fast  there  till  some  fairy  wand 
has  released  them,  and  allowed  them  to  come  to  earth 
again  ?  Well,  thousands  and  millions  of  years  ago, 
those  coals  were  plants  ;  and,  like  the  snowdrop  in 
the  garden  of  to-day,  they  caught  the  sunbeams  and 
worked  them  into  their  leaves.  Then  the  plants  died 
and  were  buried  deep  in  the  earth  and  the  sunbeams 
with  them  ;  and  like  the  gnomes  they  lay  imprisoned 
till  the  coals  were  dug  out  by  the  miners,  and  brought 
to  your  grate  ;  and  just  now  you  yourself  took  hold 
of  the  fairy  wand  which  was  to  release  them.  You 
struck  a  match,  and  its  atoms  clashing  with  atoms  of 
oxygen  in  the  air,  set  the  invisible  fairies  "  heat "  and 
**  chemical  attraction  "  to  work,  and  they  were  soon 
busy  within  the  wood  and  the  coals  causing  their 
atoms  too  to  clash  ;  and  the  sunbeams,  so  long  im- 


12 


THE  FAIRY-LAND  OF  SCIENCE. 


prisoned,  leapt  into  flame.  Then  you  spread  out  youf 
hands  and  cried,  Oh,  how  nice  and  warm ! "  and 
little  thought  that  ycu  were  warming  yourself  with 
the  sunbeams  of  ages  and  ages  ago. 

This  is  no  fancy  tale  ;  it  is  literally  true,  as  we 
shall  see  in  Lecture  VIII.,  that  the  warmth  of  a  coal 
fire  could  not  exist  if  the  plants  of  long  ago  had  not 
used  the  sunbeams  to  make  their  leaves,  holding  them 
ready  to  give  up  their  warmth  again  whenever  those 
crushed  leaves  are  consumed. 

Now,  do  you  believe  in,  and  care  for,  my  fairy-land  } 
Can  you  see  in  your  imagination  fairy  Cohesion  ever 
ready  to  lock  atoms  together  when  they  draw  very 
near  to  each  other :  or  fairy  Gravitation  dragging 
rain-drops  down  to  the  earth  :  or  the  fairy  of  Crystalli- 
zation  building  up  the  snow-flakes  in  the  clouds  }  Can 
you  picture  tiny  sunbeam-waves  of  light  and  heat 
travelling  from  the  sun  to  the  earth  ?  Do  you  care  to 
know  how  another  strange  fairy,  *  Electricity^  flings 
the  lightning  across  the  sky  and  causes  the  rumbling 
thunder  ?  Would  you  like  to  learn  how  the  sun 
makes  pictures  of  the  world  on  which  he  shines,  so 
that  w^e  can  carry  about  with  us  photographs  or 
sun-pictures  of  all  the  beautiful  scenery  of  the  earth  ? 
And  have  you  any  curiosity  about  *  Chemical  action^ 
which  works  such  wonders  in  air,  and  land,  and  sea } 
If  you  have  any  wish  to  know  and  make  friends  of 
these  invisible  forces,  the  next  question  is 

How  are  you  to  enter  the  fairy-land  rf  science  ? 

There  is  but  one  way.  Like  the  knight  or  peasant 
in  the  fairy  tales,  you  must  open  your  eyes.    There  is 


THE  FAIRY-LAND  OF  SCIENCE.  13 


no  lack  of  objects,  everything  around  you  will  tell 
some  history  if  touched  with  the  fairy  wand  of  ima- 
gination. I  have  often  thought,  w^hen  seeing  some 
sickly  child  drawn  along  the  street,  lying  on  its  back 
while  other  children  romp  and  play,  how  much  hap- 
piness might  be  given  to  sick  children  at  home  or  in 
hospitals,  if  only  they  were  told  the  stories  which  lie 
hidden  in  the  things  around  them.  They  need  not 
even  move  from  their  beds,  for  sunbeams  can  fall  on 
them  there,  and  in  a  sunbeam  there  are  stories  enough 
to  occupy  a  month.  The  fire  in  the  grate,  the  lamp 
by  the  bedside,  the  water  in  the  tumbler,  the  fly  on 
the  ceiling  above,  the  flower  in  the  vase  on  the  table, 
anything,  everything,  has  its  history,  and  can  reveal 
to  us  nature's  invisible  fairies. 

Only  you  must  wish  to  see  them.  If  you  go 
through  the  world  looking  upon  everything  only  as 
so  much  to  eat,  to  drink,  and  to  use,  you  will  never 
see  the  fairies  of  science.  But  if  you  ask  yourself  why 
things  happen,  and  how  the  great  God  above  us  has 
made  and  governs  this  world  of  ours ;  if  you  listen  to 
the  wind,  and  care  to  learn  why  it  blows  ;  if  you  ask 
the  little  flower  why  it  opens  in  the  sunshine  and 
closes  in  the  storm  ;  and  if  when  you  find  questions 
you  cannot  answer,  you  will  take  the  trouble  to  hunt 
out  in  books,  or  make  experiments,  to  solve  your  own 
questions,  then  you  will  learn  to  knov/  and  love  those 
fairies. 

Mind,  I  do  not  advise  you  to  be  constantly  asking 
questions  of  other  people;  for  often  a  question  quickly 
answered  is  quickly  forgotten,  but  a  difficulty  really 
hunted  down  is  a  triumph  for  ever.    For  example, 


THE  FAIRY-LAND  OF  SCIENCE. 


if  you  ask  why  the  rain  dries  up  from  the  grouncii 
most  likely  you  will  be  answered,  "  that  the  sun  dries 
it,"  and  you  will  rest  satisfied  with  the  sound  of  the 
words.  But  if  you  hold  a  wet  handkerchief  before 
the  fire  and  see  the  damp  rising  out  of  it,  then  you 
have  some  real  idea  how  moisture  may  be  drawn  up 
by  heat  from  the  earth. 

A  little  foreign  niece  of  mine,  only  four  years  old, 
who  could  scarcely  speak  English  plainly,  was  standing 
one  morning  near  the  bedroom  window  and  she  noticed 
the  damp  trickling  down  the  window-pane.  "  Auntie," 
she  said,  **what  for  it  rain  inside?"  It  was  quite 
useless  to  explain  to  her  in  words,  how  our  breath  had 
condensed  into  drops  of  water  upon  the  cold  glass  ; 
but  I  wiped  the  pane  clear,  and  breathed  on  it  several 
times.  When  new  drops  were  formed,  I  said,  "  Cissy 
and  auntie  have  done  like  this  all  night  in  the  room." 
She  nodded  her  little  head  and  amused  herself  for  a 
long  time  breathing  on  the  window-pane  and  watching 
the  tiny  drops  ;  and  about  a  month  later,  when  we 
were  travelling  back  to  Italy,  I  saw  her  following  the 
drops  on  the  carriage  window  with  her  little  finger, 
and  heard  her  say  quietly  to  herself,  ''Cissy  and 
auntie  made  you."  Had  not  even  this  little  child 
some  real  picture  in  her  mind  of  invisible  water  coming 
from  her  mouth,  and  making  drops  upon  the  window- 
pane  } 

Then  again,  you  must  learn  something  of  the 
language  of  science.  If  you  travel  in  a  country  with 
no  knowledge  of  its  language,  you  can  learn  very  little 
about  it :  and  in  the  same  way  if  you  are  to  go  to 


THE  FAIRY'LAND  OF  SCIENCE. 


15 


books  to  find  answers  to  your  questions,  you  must 
know  something  of  the  language  they  speak.  You 
need  not  learn  hard  scientific  names,  for  the  best 
books  have  the  fewest  of  these,  but  you  must  really 
understand  what  is  meant  by  ordinary  words. 

For  example,  how  few  people  can  really  explain 
the  difference  between  a  solid^  such  as  the  wood  of  the 
table ;  a  liqiiidy  as  water ;  and  a  gas,  such  as  I  can  let 
off  from  this  gas-jet  by  turning  the  tap.  And  yet 
any  child  can  make  a  picture  of  this  in  his  mind  if 
only  it  has  been  properly  put  before  him. 

All  matter  in  the  world  is  made  up  of  minute 
parts  or  particles  ;  in  a  solid  these  particles  are  locked 
together  so  tightly  that  you  must  tear  them  forcibly 
apart  if  you  wish  to  alter  the  shape  of  the  solid 
piece.  If  I  break  or  bend  this  wood  I  have  to  force 
the  particles  to  move  round  each  other,  and  I  have 
great  difficulty  in  doing  it.  But  in  a  liquid,  though 
the  particles  are  still  held  together,  they  do  not  cling 
so  tightly,  but  are  able  to  roll  or  glide  round  each 
other,  so  that  when  you  pour  water  out  of  a  cup  on 
to  a  table,  it  loses  its  cuplike  shape  and  spreads  itself 
out  flat.  Lastly,  in  a  gas  the  particles  are  no  longer 
held  together  at  all,  but  they  try  to  fly  away  from 
each  other ;  and  unless  you  shut  a  gas  in  tightly 
and  safely,  it  will  soon  have  spread  all  over  the 
room. 

A  solid,  therefore,  will  retain  the  same  bulk  and 
shape  unless  you  forcibly  alter  it ;  a  liquid  will  retain 
the  same  bulk,  but  not  the  same  shape  if  it  be  left 
free ;  a  gas  will  not  retain  either  the  same  bulk  or 
''he  same  shape,  but  will  spread  over  as  large  a  space 


1 6  TN£  FA  IR  Y-LA  A  D  O  F  SCIENCE, 

as  it  can  find  wherever  it  can  penetrate.  Such  simple 
things  as  these  you  must  learn  from  books  and  by 
experiment. 

Then  you  must  understand  what  is  meant  by 
chemical  attraction ;  and  though  I  can  explain  thu' 
roughly  here,  you  will  have  to  make  many  interesting 
experiments  before  you  will  really  learn  to  know  this 
wonderful  fairy  power.  If  I  dissolve  sugar  in  water, 
though  it  disappears  it  still  remains  sugar,  and  does 
not  join  itself  to  the  water.  I  have  only  to  let  the 
cup  stand  till  the  water  dries,  and  the  sugar  will 
remain  at  the  bottom.  There  has  been  no  chemical 
attraction  here. 

But  now  I  will  put  something  else  in  water  which 
will  call  up  the  fairy  power.    Here  is  a  little  piece  of 

the  metal  potassium,  one 
of  the  simple  substances 
of  the  earth  ;  that  is  to 
say,  we  cannot  split  it 
up  into  other  substances, 
wherever  we  find  it,  it  is 
always  the  same.    Now  if 

Piece  of  potassium  in  a  basin  of     I  put  this  piece  of  potas- 

slum  on  the  water  it  does 
not  disappear  quietly  like  the  sugar.  See  how  it  rolls 
round  and  round,  fizzing  violently,  with  a  blue  flame 
burning  round  it,  and  at  last  goes  off  with  a  pop. 

What  has  been  happening  here } 

You  must  first  know  that  water  is  made  of  two 
substances,  hydrogen  and  oxygen,  and  these  are  not 
merely  held  together,  but  are  joined  so  completely 
that  they  have  lost  themselves  and  have  become 


Fig.  I. 


THE  FAIRY-LAND  OF  SCIENCE, 


17 


water  ;  and  each  atom  of  water  is  made  of  two  atoms 
of  hydrogen  and  one  of  oxygen. 

Now  the  metal  potassium  is  devotedly  fond  of 
oxygen,  and  the  moment  I  threw  it  on  the  water  it 
called  the  fairy  chemical  attraction  "  to  help  it,  and 
dragged  the  atoms  of  oxygen  out  of  the  water  and 
joined  them  to  itself.  In  doing  this  it  also  caught  part 
of  the  hydrogen,  but  only  half,  and  so  the  rest  was 
left  out  in  the  cold.  No,  not  in  the  cold !  for  the 
potassium  and  oxygen  made  such  a  great  heat  in 
clashing  together  that  the  rest  of  the  hydrogen 
became  very  hot  indeed,  and  sprang  into  the  air  to 
find  some  other  companion  to  make  up  for  what  it 
had  lost.  Here  it  found  some  free  oxygen  floating 
about,  and  it  seized  upon  it  so  violently,  that  they 
made  a  burning  flame,  wbile  the  potassium  with  its 
newly  found  oxygen  and  hydrogen  sank  down  quietly 
into  the  water  as  potash.  And  so  you  see  we  have 
got  quite  a  new  substance  potash  in  the  basin  ;  made 
with  a  great  deal  of  fuss  by  chemical  attraction  drawing 
different  atoms  together. 

When  you  can  really  picture  this  power  to  yourself 
it  will  help  you  very  much  to  understand  what  you 
read  and  observe  about  nature. 

Next,  as  plants  grow  around  you  on  every  side, 
and  are  of  so  much  importance  in  the  world,  you  must 
also  learn  something  of  the  names  of  the  different 
parts  of  a  flower,  so  that  you  may  understand  those 
books  which  explain  how  a  plant  grows  and  lives  and 
forms  its  seeds.  You  must  also  know  the  common 
names  of  the  parts  of  an  animal,  and  of  your  own 
body,  so  that  you  may  be  interested  in  understand- 


1 8  THE  FA  IR  Y-LA  ND  OF  SCIENCE. 


ing  the  use  of  the  different  organs  ;  how  you  breathe, 
and  how  your  blood  flows;  how  one  animal  walks, 
another  flies,  and  another  swims.  Then  you  must 
learn  something  of  the  various  parts  of  the  world,  so 
that  you  may  know  what  is  meant  by  a  river,  a  plain, 
a  valley,  or  a  delta.  All  these  things  are  not  difficult, 
you  can  learn  them  pleasantly  from  simple  books  on 
physics,  chemistry,  botany,  physiology,  and  physical 
geography ;  and  when  you  understand  a  few  plain 
scientific  terms,  then  all  by  yourself,  if  you  will  open 
your  eyes  and  ears,  you  may  wander  happily  in  the 
fairy-land  of  science.  Then  wherever  you  go  you 
will  find 

**  Tongues  in  trees,  books  in  the  running  brooks, 
Sermons  in  stones,  and  good  in  everything.'* 

And  now  we  come  to  the  last  part  of  our  subject. 
When  you  have  reached  and  entered  the  gates  of 
science,  how  are  you  to  use  and  enjoy  this  new  and 
beautiful  land } 

This  is  a  very  important  question,  for  you  may 
make  a  twofold  use  of  it.  If  you  are  only  ambitious 
to  shine  in  the  world,  you  may  use  it  chiefly  to  get 
prizes,  to  be  at  the  top  of  your  class,  or  to  pass  in 
examinations  ;  but  if  you  also  enjoy  discovering  its 
secrets,  and  desire  to  learn  more  and  more  of  nature, 
and  to  revel  in  dreams  of  its  beauty,  then  you  will  study 
science  for  its  own  sake  as  well.  Now  it  is  a  good 
thing  to  win  prizes  and  be  at  the  top  of  your  class, 
for  it  shows  that  you  are  industrious ;  it  is  a  good 
thing  to  pass  well  in  examinations,  for  it  shows  that 
you  are  accurate ;  but  if  you  study  science  for  this 


THE  FAIRY-LAND  OF  SCIENCE,  19 

reason  only,  do  not  complain  if  you  find  it  dull,  and 
dry, -and  hard  to  master.  You  may  learn  a  great  deal 
that  is  useful,  and  nature  will  answer  you  truthfully 
if  you  ask  your  questions  accurately,  but  she  will  give 
you  dry  facts,  just  such  as  you  ask  for.  If  you  do 
not  love  her  for  herself  she  will  never  take  you  to  her 
heart. 

This  is  the  reason  why  so  many  complain  that 
science  is  dry  and  uninteresting.  They  forget  that 
though  it  is  necessary  to  learn  accurately,  for  so  only 
we  can  arrive  at  truth,  it  is  equally  necessary  to  love 
knowledge  and  make  it  lovely  to  those  who  learn,  and 
to  do  this  we  must  get  at  the  spirit  which  lies  under 
the  facts.  What  child  which  loves  its  mother's  face 
is  content  to  know  only  that  she  has  brown  eyes,  a 
straight  nose,  a  small  mouth,  and  hair  arranged  in 
such  and  such  a  manner }  No,  it  knows  that  its 
mother  has  the  sweetest  smile  of  any  woman  living ; 
that  her  eyes  are  loving,  her  kiss  is  sweet,  and  that 
when  she  looks  grave,  then  something  is  wrong  which 
must  be  put  right.  And  it  is  in  this  way  that  those 
who  wish  to  enjoy  the  fairy-land  of  science  must  love 
nature. 

It  is  well  to  know  that  when  a  piece  of  potassium 
is  thrown  on  water  the  change  which  takes  place  is 
expressed  by  the  formula  K  +  H2  O  =  K  H  O  +  H. 
But  it  is  better  still  to  have  a  mental  picture  of  the 
tiny  atoms  clasping  each  other,  and  mingling  so  as  to 
make  a  new  substance,  and  to  feel  how  wonderful  are 
the  many  changing  forms  of  nature.  It  is  useful  to 
be  able  to  classify  a  flower  and  to  know  that  the 
butte«*cup  belongs  to  the  Family  Ranunculaceae,  with 


20 


THE  FAIRY'LAND  OF  SCIENCE. 


petals  free  a7td  defiiiite,  stamens  liypogynous  and 
indefinite,  pistil  apocarpous.  But  it  is  far  sweeter  to 
learn  about  the  life  of  the  little  plant,  to  understand 
why  its  peculiar  flower  is  useful  to  it,  and  how  it 
feeds  itself,  and  makes  its  seed.  No  one  can  love  dry 
fig.  2.  fixcis  ;  we  must  clothe 

them  with  real  mean- 
uv^  and  love  the  truths 
they  tell,  if  we  wish  to 
enjoy  science. 

Let  us  take  an  ex- 
ample to  show  this. 
I  have  here  a  branch 
of  white  coral,  a  beau- 
tiful, delicate  piece  of 
nature's  work.  We 
will  begin  by  copy- 
ing a  description  of 
it  from  one  of  those 
class-books  which  sup- 
pose children  to  learn 
words  like  parrots, 
and  to  repeat  them 
with  just  as  little  un- 
derstanding. 

Coral  is  formed  by 
an  animal  belonging 
to  the  kingdom  cl 
Radiates,  sub-kingdom  Polypes.  The  soft  body  of 
the  animal  is  attached  to  a  support,  the  mouth 
opening  upwards  in  a  row  of  tentacles.  The  coral 
is  secreted  in  the  body  of  the  polyp  out  of  the 


Piece  of  white  coraL 


THE  FAIRY-LAND  OF  SCIENCE. 


21 


carbonate  of  lime  in  the  sea.  Thus  the  coral  animal* 
cule>ears  its  polypidom  or  rocky  structure  in  warm 
latitudes,  and  constructs  reefs  or  barriers  round  islands. 
It  is  limited  in  range  of  depth  from  25  to  30  fathoms 
Chemically  considered,  coral  is  carbonate  ot  lime ; 
physiologically,  it  is  the  skeleton  of  an  animal  ;  geo- 
graphically, it  is  characteristic  of  warm  latitudes, 
especially  of  the  Pacific  Ocean."  This  description 
is  correct,  and  even  very  fairly  complete,  if  you 
know  enough  of  the  subject  to  understand  it.  But 
tell  me,  does  it  lead  you  to  love  my  piece  of  coral  ? 
Have  you  any  picture  in  your  mind  of  the  coral 
animal,  its  home,  or  its  manner  of  working  ? 

But  now,  instead  of  trying  to  master  this  dry,  hard 
passage,  take  Mr.  Huxley's  penny  lecture  on  'Coral 
and  Coral  Reefs,'*  and  with  the  piece  of  coral  in 
your  hand,  try  really  to  learn  its  history.  You  will 
then  be  able  to  picture  to  yourself  the  coral  animal 
as  a  kind  of  sea-anemone,  something  like  those  which 
you  have  often  seen,  like  red,  blue,  or  green  flowers, 
putting  out  their  feelers  in  sea-water  on  our  coasts, 
and  drawing  in  the  tiny  sea-animals  to  digest  them 
in  that  bag  of  fluid  which  serves  the  sea-anemone  as 
a  stomach.  You  will  learn  how  this  curious  jelly 
animal  can  split  itself  in  two,  and  so  form  two  polyps, 
or  send  a  bud  out  of  its  side  and  so  grow  up  into  a 
kind  of  "tree  or  bush  of  polyps,"  or  how  it  can  hatch 
little  eggs  inside  it  and  throw  out  young  ones  from 
its  mouth,  provided  with  little  hairs,  by  means  of 
which  they  swim  to  new  resting-places.    You  will 

•  *  Manchf^ster  Science  Lectures,'  No.  I,  Second  Series.  John  Hey« 
vood,  141,  L>eans<iate,  Manche.sier. 


22  THE  FAIRY-LAND  OF  SCIENCE. 


learn  the  difference  between  the  animal  which  builds 
up  the  red  coral  as  its  skeleton,  and  the  group  of 
animals  which  build  up  the  white ;  and  you  will  look 
with  new  interest  on  our  piece  of  white  coral,  as  you 
read  that  each  of  those  little  cups  on  its  stem  with 
delicate  divisions  like  the  spokes  of  a  wheel  has  been 
the  home  of  a  separate  polyp,  and  that  from  the  sea- 
water  each  little  jelly  animal  has  drunk  in  carbonate 
of  lime  as  you  drink  in  sugar  dissolved  in  water,  and 
then  has  used  it  grain  by  grain  to  build  that  delicate 
cup  and  add  to  the  coral  tree. 

We  cannot  stop  to  examine  all  about  coral  now,  we 
are  only  learning  how  to  learn,  but  surely  our  speci- 
men is  already  beginning  to  grow  interesting ;  and 
when  you  have  followed  it  out  into  the  great  Pacific 
Ocean,  where  the  wild  waves  dash  restlessly  against 
the  coral  trees,  and  have  seen  these  tiny  drops  of  jelly 
conquering  the  sea  and  building  huge  walls  of  stone 
against  the  rough  breakers,  you  will  hardly  rest  till 
you  know  all  their  history.  Look  at  that  curious  cir- 
cular island  in  the  picture  (Fig.  3),  covered  with  palm 
trees ;  it  has  a  large  smooth  lake  in  the  middle,  and 
the  bottom  of  this  lake  is  covered  with  blue,  red,  and 
green  jelly  animals,  spreading  out  their  feelers  in  the 
water  and  looking  like  beautiful  flowers,  and  all  round 
the  outside  of  the  island  similar  animals  are  to  be 
seen  washed  by  the  sea  waves.  Such  islands  as  this 
have  been  built  entirely  by  the  coral  animals,  and  the 
history  of  the  way  in  which  the  reefs  have  sunk  gra- 
dually down,  as  the  tiny  creatures  added  to  them  inch 
by  inch,  is  as  fascinating  as  the  story  of  the  building 
of  any  fairy  palace  in  the  days  of  old.    Read  all  this, 


THE  FAIRY'LAND  OF  SCIENCE, 


23 


and  then  if  you  have  no  coral  of  your  own  to  examine, 
go  to  the  British  Museum  *  and  see  the  beautiful  spe- 
cimens in  the  glass  cases  there,  and  think  that  they 

Fig.  3. 


Coral  island  in  the  Pacific. 


have  been  built  up  under  the  rolling  surf  by  the  tiny 
jelly  animals ;  and  then  coral  will  become  a  real  living 
thing  to  you,  and  you  will  love  the  thoughts  it  awakens. 

But  people  often  ask,  what  is  the  use  of  learning 
all  this  1  If  you  do  not  feel  by  this  time  how  delight- 
ful it  is  to  fill  your  mind  with  beautiful  pictures  of 
nature,  perhaps  it  would  be  useless  to  say  more.  But 
in  this  age  of  ours,  when  restlessness  and  love  of  ex- 
citement pervade  so  many  lives,  is  it  nothing  to  be 
taken  out  of  ourselves  and  made  to  look  at  the 

*  These  specimens  are  eventually  going  to  South  Kensington. 


24 


THE  FAIRY'LAND  OF  SCIENCE, 


wonders  of  nature  going  on  around  us  ?  Do  you 
never  feel  tired  and  out  of  sorts/'  and  want  to  creep 
away  from  your  companions,  because  they  are  merry 
and  you  are  not  ?  Then  is  the  time  to  read  about 
the  stars,  and  how  quietly  they  keep  their  course 
from  age  to  age  ;  or  to  visit  some  Httle  flower,  and 
ask  what  story  it  has  to  tell  ;  or  to  watch  the  clouds, 
and  try  to  imagine  how  the  winds  drive  them  across 
the  sky.  No  person  is  so  independent  as  he  who  can 
find  interest  in  a  bare  rock,  a  drop  of  water,  the  foam 
of  the  sea,  the  spider  on  the  wall,  the  flower  under- 
foot or  the  stars  overhead.  And  these  interests  are 
open  to  everyone  who  enters  the  fairy-land  of  science. 

Moreover,  we  learn  from  this  study  to  see  that  there 
is  a  law  and  purpose  in  everything  in  the  Universe, 
and  it  makes  us  patient  when  we  recognize  the  quiet 
noiseless  working  of  nature  all  around  us.  Study 
light,  and  learn  how  all  colour,  beauty,  and  life  depend 
on  the  sun's  rays  ;  note  the  winds  and  currents  of  the 
air,  regular  even  in  their  apparent  irregularity,  as  they 
carry  heat  and  moisture  all  over  the  world.  Watch 
the  water  flowing  in  deep  quiet  streams,  or  forming 
the  vast  ocean  ;  and  then  reflect  that  every  drop  is 
guided  by  invisible  forces  working  according  to  fixed 
laws.  See  plants  springing  up  under  the  sunlight, 
learn  the  secrets  of  plant  life,  and  how  their  scents 
and  colours  attract  the  insects.  Read  how  insects 
cannot  live  without  plants,  nor  plants  without  the 
flitting  butterfly  or  the  busy  bee.  Realize  that  all 
this  is  worked  by  fixed  laws,  and  that  out  of  it  (even 
if  sometimes  in  sufiering  and  pain)  springs  the  wonder- 
ful universe  around  us.    And  then  say,  can  you  fear 


THE  FAIRY-LAND  OF  SCIENCE. 


25 


for  your  own  little  life,  even  though  it  may  have  its 
troubles  ?  Can  you  help  feeling  a  part  of  this  guided 
and  governed  nature  ?  or  doubt  that  the  power  which 
fixed  the  laws  of  the  stars  and  of  the  tiniest  drop  of 
water — that  made  the  plant  draw  power  from  the  sun, 
the  tiny  coral  animal  its  food  from  the  dashing  waves  ; 
that  adapted  the  flower  to  the  insect  and  the  insect 
to  the  flower — is  also  moulding  your  life  as  part  of 
the  great  machinery  of  the  universe,  so  that  you  have 
only  to  work,  and  to  wait,  and  to  love  ? 

We  are  all  groping  dimly  for  the  Unseen  Power,  but 
no  one  who  loves  nature  and  studies  it  can  ever  feel 
alone  or  unloved  in  the  world.  Facts,  as  mere  facts, 
are  dry  and  barren,  but  nature  is  full  of  life  and  love, 
and  her  calm  unswerving  rule  is  tending  to  some  great 
though  hidden  purpose.  You  may  call  this  Unseen 
Power  what  you  will — may  lean  on  it  in  loving, 
trusting  faith,  or  bend  in  reverent  and  silent  awe  ;  but 
even  the  little  child  who  lives  with  nature  and  gazes 
on  her  with  open  eye,  must  rise  in  some  sense  or  other 
through  nature  to  nature's  God. 


3 


26 


THE  FAIRY'LAND  OF  SCIENCE. 


LECTURE  II. 


SUNBEAMS  AND  THE  WORK  THEY  DO. 


and  merrier  as  he  watches  them 
playing  on  the  wall,  sparkling  like  diamonds  on 
the  ripples  of  the  sea,  or  making  bows  of  coloured 
light  on  the  waterfall  ?  Is  not  the  sunbeam  so  dear  to 
us  that  it  has  become  a  household  word  for  all  that  is 
merry  and  gay  ?  and  when  we  want  to  describe  the 


SUNBEAMS  AND  THEIR  WORK,  2J 


desti  est,,  busiest  little  sprite  amongst  us,  who  wakes  a 
smile  on  all  faces  wherever  she  goes,  do  we  not  call 
her  the  "  sunbeam  of  the  house  "  ? 

And  yet  how  little  even  the  wisest  among  us  know 
about  the  nature  and  work  of  these  bright  messengers 
of  the  sun  as  they  dart  across  space  ! 

Did  you  ever  wake  quite  early  in  the  morning, 
when  it  was  pitch-dark  and  you  could  see  nothing, 
not  even  your  own  hand  ;  and  then  lie  watching  as  time 
went  on  till  the  light  came  gradually  creeping  in  at 
the  window  ?  If  you  have  done  this  you  will  have 
noticed  that  you  can  at  first  only  just  distinguish  the 
dim  outline  of  the  furniture  ;  then  you  can  tell  the  dif- 
ference between  the  white  cloth  on  the  table  and  the 
dark  wardrobe  beside  it  ;  then  by  degrees  all  the 
smaller  details,  the  handles  of  the  drawer,  the  pattern 
on  the  wall,  and  the  different  colours  of  all  the  objects 
in  the  room  become  clearer  and  clearer  till  at  last 
you  see  all  distinctly  in  broad  daylight. 

What  has  been  happening  here  ?  and  why  have  the 
things  in  the  room  become  visible  by  such  slow 
degrees  ?  We  say  that  the  sun  is  rising,  but  we  know 
very  well  that  it  is  not  the  sun  which  moves,  but  that 
our  earth  has  been  turning  slowly  round,  and  bringing 
the  little  spot  on  which  we  live  face  to  face  with  the 
great  fiery  ball,  so  that  his  beams  can  fall  upon  us. 

Take  a  small  globe,  and  stick  a  piece  of  black 
plaster  over  England,  then  let  a  lighted  lamp  repre- 
sent the  sun,  and  turn  the  globe  slowly,  so  that  the 
spot  creeps  round  from  the  dark  side  away  from  the 
lamp,  until  it  catches,  first  the  rays  which  pass  along 
the  side  of  the  globe,  then  the  more  direct  rays,  and 


28  THE  FAIRY-LAND  OF  SCIENCE. 


at  last  stands  fully  in  the  blaze  of  the  light  Just  this 
was  happening  to  our  spot  of  the  world  as  you  lay  in 
bed  and  saw  the  light  appear  ;  and  we  have  to  learn 
to-day  what  those  beams  are  which  fall  upon  us 
and  what  they  do  for  us. 

First  we  must  learn  something  about  the  sun  itself, 
since  it  is  the  starting-place  of  all  the  sunbeams.  If 
the  sun  were  a  dark  mass  instead  of  a  fiery  one  we 
should  have  none  of  these  bright  cheering  messengers, 
and  though  we  were  turned  face  to  face  with  him  every 
day  we  should  remain  in  one  cold  eternal  night.  Now 
you  will  remember  we  mentioned  in  the  last  lecture 
that  it  is  heat  which  shakes  apart  the  little  atoms  of 
water  and  makes  them  float  up  in  the  air  to  fall  again 
as  rain  ;  and  that  if  the  day  is  cold  they  fall  as  snow, 
and  all  the  water  is  turned  into  ice.  But  if  the  sun 
were  altogether  dark,  think  how  bitterly  cold  it  would 
be  ;  far  colder  than  the  most  wintry  weather  ever 
known,  because  in  the  bitterest  night  some  warmth 
comes  out  of  the  earth,  where  it  has  been  stored  from 
the  sunlight  which  fell  during  the  day.  But  if  we 
never  received  any  warmth  at  all,  no  water  would 
ever  rise  up  into  the  sky,  no  rain  ever  fall,  no  rivers 
flow,  and  consequently  no  plants  could  grow  and  no 
animals  live.  All  water  would  be  in  the  form  of  snow 
and  ice,  and  the  earth  would  be  one  great  frozen  mass 
with"  nothing  moving  upon  it. 

So  you  see  it  becomes  very  interesting  for  us  to  learn 
what  the  sun  is,  and  how  he  sends  us  his  beams. 
How  far  away  from  us  do  you  think  he  is  ?  On  a 
fine  summer's  day  when  we  can  see  him  clearly,  it 
looks  as  if  we  had  only  to  get  into  a  balloon  and 


SUNBEAMS  AND  THEIR  WORK, 


29 


reach  him  as  he  sits  in  the  sky,  and  yet  we  know 
roughly  that  he  is  more  than  ninety-one  millions  of 
miles  distant  from  our  earth. 

These  figures  are  so  enormous  that  you  cannot 
really  grasp  them.  But  imagine  yourself  in  an  express 
train,  travelling  at  the  tremendous  rate  of  sixty  miles 
an  hour  and  never  stopping.  At  that  rate,  if  you 
wished  to  arrive  at  the  sun  to-day  you  would  have 
been  obliged  to  start  171  years  ago.  That  is,  you 
must  have  set  off  in  the  early  part  of  the  reign  of 
Queen  Anne,  and  you  must  have  gone  on,  never,  never 
resting,  through  the  reigns  of  George  I.,  George  II., 
and  the  long  reign  of  George  III.,  then  through  those 
of  George  IV.,  William  IV.,  and  Victoria,  whirling  on 
day  and  night  at  express  speed,  and  at  last,  to-day, 
you  would  have  reached  the  sun  ! 

And  when  you  arrived  there,  how  large  do  you 
think  you  would  find  him  to  be  }  Anaxagoras,  a 
learned  Greek,  was  laughed  at  by  all  his  fellow  Greeks 
because  he  said  that  the  sun  was  as  large  as  the 
Peloponnesus,  that  is  about  the  size  of  Middlesex, 
How  astonished  they  would  have  been  if  they  could 
"have  known  that  not  only  is  he  bigger  than  the  whole 
of  Greece,  but  more  than  a  million  times  bigger  than 
the  whole  world ! 

Our  world  itself  is  a  very  large  place,  so  large  that 
our  own  country  looks  only  like  a  tiny  speck  upon  it,  and 
an  express  train  would  take  nearly  a  month  to  travel 
round  it.  Yet  even  our  whole  globe  is  nothing  in  size 
compared  to  the  sun,  for  it  only  measures  8000  miles 
across,  while  the  sun  measures  more  than  852,000. 

Imagine  for  a  moment  that  you  could  cut  the  sun  and 


50  THE  FAIRY-LAND  QF  SCIENCE. 


the  earth  each  in  half  as  you  would  cut  an  apple;  then 
if  you  were  to  lay  the  flat  side  of  the  half-earth  on  the 
flat  side  of  the  half-sun  it  would  take  io6  such  earths 
to  stretch  across  the  face  of  the  sun.  One  of  these  io6 

Fig.  4. 


106  earths  laid  acrogs  the  face  of  the  sun.  Each  one  oJ  th«w  dotLi 
represents  rou<^jhly  the  size  of  the  earth  as  compmed  to  the  siie  of  the 
sun  represented  by  the  large  circle. 


round  spots  on  the  diagram  represents  the  size  which 
our  earth  would  look  if  placed  on  the  sun ;  and  they 
are  so  tiny  compared  to  him  that  they  look  only  like 
a  string  of  minute  beads  stretched  across  his  face 


SUNBEAMS  AND  THEIR  WORK, 


31 


Only  think,  then,  how  many  of  these  minute  dots 
would  be  required  to  fill  the  whole  of  the  inside  of 
Fig.  4,  if  it  were  a  globe  ! 

One  of  the  best  ways  to  form  an  idea  of  the  whole 
size  of  the  sun  is  to  imagine  it  to  be  hollow,  like  an 
air-ball,  and  then  see  how  many  earths  it  would  take 
to  fill  it.  You  would  hardly  believe  that  it  would  take 
one  million,  three  hundred  and  thirty-one  thousand 
globes  the  size  of  our  world  squeezed  together. 
Just  think,  if  a  huge  giant  could  travel  all  over  the 
universe  and  gather  worlds,  all  as  big  as  ours,  and 
were  to  make  first  a  heap  of  merely  ten  such  worlds, 
how  huge  it  would  be  !  Then  he  must  have  a  hundred 
such  heaps  of  ten  to  make  a  thousand  worlds  ;  and 
then  he  must  collect  ai<ain  a  thoiLsand  times  that 
thousand  to  make  a  million,  and  when  he  had  stuffed 
them  all  into  the  sun-ball  he  would  still  have  only 
filled  three-quarters  of  it ! 

After  hearing  this  you  will  not  be  astonished  that 
such  a  monster  should  give  out  an  enormous  quantity 
of  light  and  heat  ;  so  enormous  that  it  is  almost  im- 
possible to  form  any  idea  of  it.  Sir  John  Herschel 
has,  indeed,  tried  to  picture  it  for  us.  He  found  that 
a  ball  of  lime  with  a  flame  of  oxygen  and  hydrogen 
playing  round  it  (such  as  we  use  in  magic  lanterns 
and  call  oxy-hydrogen  light)  becomes  so  violently 
hot  that  it  gives  the  most  brilliant  artificial  light  we 
can  get — such  that  you  cannot  put  your  eye  near 
it  without  injury.  Yet  if  you  wanted  to  have  a  light 
,is  strong  as  that  of  our  sun,  it  would  not  be  enough 
to  make  such  a  lime-ball  as  big  as  the  sun  is.  No, 
you  must  make  it  as  big  as  146  suns,  or  more  than 


32 


THE  FAIRY-LAND  OF  SCIENCE, 


146,000,000  times  as  h\g  as  our  earth,  in  order  to  get 
the  right  amount  of  light.  Then  you  would  have  a 
tolerably  good  artificial  sun  ;  for  we  know  that  the 
body  of  the  sun  gives  out  an  intense  white  light,  just 
as  the  lime-ball  does,  and  that,  like  it,  it  has  an  atmo- 
sphere of  glowing  gases  round  it 

But  perhaps  we  get  the  best  idea  of  the  mighty 
heat  and  light  of  the  sun  by  remembering  how  few  of 
the  rays  which  dart  out  on  all  sides  from  this  fiery 
ball  can  reach  our  tiny  globe,  and  yet  how  powerful 
they  are.  Look  at  the  globe  of  a  lamp  in  the  middle  of 
the  room,  and  see  how  its  light  pours  out  on  all  sides 
and  into  every  corner;  then  take  a  grain  of  mustard- 
seed,  which  will  very  well  represent  the  comparative 
size  of  our  earth,  and  hold  it  up  at  a  distance  from  the 
lamp.  How  very  few  of  all  those  rays  which  are 
filling  the  room  fall  on  the  little  mustard-seed,  and 
just  so  few  does  our  earth  catch  of  the  rays  which 
dart  out  from  the  sun.  And  yet  this  small  quantity 
(g-x^Vir-niillionth  part  of  the  whole)  does  nearly  all  the 
work  of  our  world.* 

In  order  to  see  how  powerful  the  sun's  rays  are, 
you  have  only  to  take  a  magnifying  glass  and  gather 
them  to  a  point  on  a  piece  of  brown  paper,  for  they 
will  set  the  paper  alight.  Sir  John  Herschel  tells  us 
that  at  the  Cape  of  Good  Hope  the  heat  was  even 
so  great  that  he  cooked  a  beefsteak  and  roasted  some 
eggs  by  merely  putting  them  in  the  sun,  in  a  box 
with  a  glass  lid!    Indeed,  just  as  we  should  all  be 

*  These  and  the  preceding  numerical  statements  will  be  found  worked 
out  in  Sir  J  Ilerschel's  'Familiar  Lectures  on  Scientific  Subjects,'  1868, 
from  which  many  of  the  facts  in  the  first  part  of  the  lecture  are  taken. 


SUNBEAMS  AND  THEIR  WORK. 


33 


frozen  to  death  if  the  sun  were  cold,  so  we  should 
all  be  burnt  up  with  intolerable  heat  if  his  fierce  rays 
fell  with  all  their  might  upon  us.  But  we  have  an 
invisible  veil  protecting  us,  made — of  what  do  you 
think  ?  Of  those  tiny  particles  of  water  which  the 
sunbeams  draw  up  and  scatter  in  the  air,  and  which, 
as  we  shall  see  in  Lecture  IV.,  cut  off  part  of  the  in- 
tense heat  and  make  the  air  cool  and  pleasant  for  us. 

We  have  now  learnt  something  of  the  distance,  the 
size,  the  light,  and  the  heat  of  the  sun — the  great 
source  of  the  sunbeams.  But  we  are  as  yet  no  nearer 
the  answer  to  the  question.  What  is  a  sunbeam  1  how 
does  the  sun  touch  our  earth  } 

Now  suppose  I  wish  to  touch  you  from  this  plat- 
form where  I  stand,  I  can  do  it  in  two  ways.  Firstly, 
I  can  throw  something  at  you  and  hit  you — in  this 
case  a  tiling  will  have  passed  across  the  space  from 
me  to  you.  Or,  secondly,  if  I  could  make  a  violent 
movement  so  as  to  shake  the  floor  of  the  room,  you 
would  feel  a  quivering  motion  ;  and  so  I  should  touch 
you  across  the  whole  distance  of  the  room.  But  in 
this  case  no  tJdng  would  have  passed  from  me  to  you 
but  a  movement  or  wave^  which  passed  along  the 
boards  of  the  floor.  Again,  if  I  speak  to  you,  how 
does  the  sound  reach  your  ear }  Not  by  anything 
being  thrown  from  my  mouth  to  your  ear,  but  by 
the  motion  of  the  air.  When  I  speak  I  agitate  the 
air  near  my  mouth,  and  that  makes  a  wave  in  the 
air  beyond,  and  that  one,  another,  and  another  (as 
we  shall  see  more  fully  in  Lecture  VI.),  till  the  last 
wave  hits  the  drum  of  your  ear. 


34 


THE  FAIRY-LAND  OF  SCIENCE, 


Thus  we  see  there  are  two  ways  of  touching  any- 
thing at  a  distance  ;  ist,  by  throwing  some  thing  at  it 
and  hitting  it ;  2nd,  by  sending  a  movement  or  wave 
across  to  it,  as  in  the  case  of  the  quivering  boards  and 
the  air. 

Now  the  great  natural  philosopher  Newton  thought 
that  the  sun  touched  us  in  the  first  of  these  ways,  and 
that  sunbeams  were  made  of  very  minute  atoms  of 
matter  thrown  out  by  the  sun,  and  making  a  perpetual 
cannonade  on  our  eyes.  It  is  easy  to  understand 
that  this  would  make  us  see  light  and  feel  heat,  just  as 
a  blow  in  the  eye  makes  us  see  stars,  or  on  the  body 
makes  it  feel  hot :  and  for  a  long  time  this  explana- 
tion was  supposed  to  be  the  true  one.  But  we  know 
now  that  there  are  many  facts  which  cannot  be 
explained  on  this  theory,  though  we  cannot  go  into 
them  here.  What  we  will  do,  is  to  try  and  under- 
stand what  now  seems  to  be  the  true  explanation  of 
a  sunbeam. 

About  the  same  time  that  Newton  wrote,  a  Dutch- 
man, named  Huyghens,  suggested  that  light  comes 
from  the  sun  in  tiny  waves,  travelling  across  space 
much  in  the  same  way  as  ripples  travel  across  a  pond. 
The  only  difficulty  was  to  explain  in  what  substance 
these  waves  could  be  travelling :  not  through  water, 
for  we  know  that  there  is  no  water  in  space — nor 
through  air,  for  the  air  stops  at  a  comparatively  short 
Jistance  from  our  earth.  There  must  then  be  some- 
thing filling  all  space  between  us  and  the  sun,  finer 
than  either  water  or  air. 

And  now  I  must  ask  you  to  use  all  your  imagtna 
tion,  for  I  want  you  to  picture  to  yourselves  something 


SUNBEAMS  AND  FHEIR  WORK, 


35 


quite  as  invisible  as  the  Emperor*s  new  clothes  in 
Andersen's  fairy-tale,  only  with  this  difference,  that 
our  invisible  something  is  very  active  ;  and  though  we 
can  neither  see  it  nor  touch  it  we  know  it  by  its 
effects.  You  must  imagine  a  fine  substance  filling  all 
space  between  us  and  the  sun  and  the  stars.  A 
substance  so  very  delicate  and  subtle,  that  not  only  is 
it  invisible,  but  it  can  pass  through  solid  bodies  such 
as  glass,  ice,  or  even  wood  or  brick  walls.  This 
substance  we  call  "ether.'*  I  cannot  give  you  here 
the  reasons  why  we  must  assume  that  it  is  throughout 
all  space ;  you  must  take  this  on  the  word  of  such 
men  as  Sir  John  Herschel  or  Professor  Clerk-Maxwell, 
until  you  can  study  the  question  for  yourselves. 

Now  if  you  can  imagine  this  ether  filling  every 
corner  of  space,  so  that  it  is  everywhere  and  passes 
through  everything,  ask  yourselves,  what  must  happen 
when  a  great  commotion  is  going  on  in  one  of  the 
large  bodies  which  float  in  it  ^  When  the  atoms  of 
the  gases  round  the  sun  are  clashing  violently  together 
to  make  all  its  light  and  heat,  do  you  not  think  they 
must  shake  this  ether  all  around  them  And  then, 
since  the  ether  stretches  on  all  sides  from  the  sun  to 
our  earth  and  all  other  planets,  must  not  this  quiver- 
ing travel  to  us,  just  as  the  quivering  of  the  boards 
would  from  me  to  you  }  Take  a  basin  of  water  to 
represent  the  ether,  and  take  a  piece  of  potassium  like 
that  which  we  used  in  our  last  lecture,  and  hold  it 
with  a  pair  of  nippers  in  the  middle  of  the  water. 
You  will  see  that  as  the  potassium  hisses  and  the 
flame  burns  round  it,  they  will  make  waves  which 
will  travel  all  over  the  water  to  the  edge  of  the  basin, 


36 


THE  FATRY-LAND  OF  SCIENCE, 


and  you  can  imagine  how  in  the  same  way  waves 
travel  over  the  ether  from  the  sun  to  us. 

Straight  away  from  the  sun  on  all  sides,  never 
stopping,  never  resting,  bat  chasing  after  each  other 
with  marvellous  quickness,  these  tiny  waves  travel 
out  into  space  by  night  and  by  day.  When  our  spot 
of  the  earth  where  England  lies  is  turned  away  from 
them  and  they  cannot  touch  us,  then  it  is  night  for  us, 
but  directly  England  is  turned  so  as  to  face  the  sun, 
then  they  strike  on  the  land,  and  the  water,  and  warm 
it ;  or  upon  our  eyes,  making  the  nerves  quiver  so  that 
we  see  Hght.  Look  up  at  the  sun  and  picture  to 
yourself  that  instead  of  one  great  blow  from  a  fist 
causing  you  to  see  stars  for  a  moment,  millions  of 
tiny  blows  from  these  sun-waves  are  striking  every 
instant  on  your  eye  ;  then  you  will  easily  understand 
that  this  would  cause  you  to  see  a  constant  blaze  of 
light. 

But  when  the  sun  is  away,  if  the  night  is  clear  we 
have  light  from  the  stars.  Do  these  then  too  make 
waves  all  across  the  enormous  distance  between  them 
and  us  ?  Certainly  they  do,  for  they  too  are  suns  like 
our  own,  only  they  are  so  far  off  that  the  waves  they 
send  are  more  feeble,  and  so  we  only  notice  them 
when  the  sun's  stronger  waves  are  away. 

But  perhaps  you  will  ask,  if  no  one  has  ever  seen 
these  waves  nor  the  ether  in  which  they  are  made,  what 
right  have  we  to  say  they  are  there  }  Strange  as  it  may 
seem,  though  we  cannot  see  them  we  have  measured 
them  and  know  how  large  they  are,  and  how  many 
can  go  into  an  inch  of  space.  For  as  these  tiny  waves 
3re  running  on  straight  forward  through  the  room,  if 
we  put  something  in  their  way,  thev  will  have  to  run 


SUNBEAMS  AND  THEIR  WORK. 


37 


round  it ;  and  if  you  let  in  a  very  narrow  ray  of  light 
through  a  shutter  and  put  an  upright  wire  in  the 
sunbeam,  you  actually  make  the  waves  run  round  the 
wire  just  as  water  runs  round  a  post  in  a  river;  and 
they  meet  behind  the  wire,  just  as  the  water  meets  in  a 
V  shape  behind  the  post.  Now  when  they  meet,  they 
run  up  against  each  other,  and  here  it  is  we  catch 
them.  For  if  they  meet  comfortably,  both  rising  up 
in  a  good  wave,  they  run  on  together  and  make  a 
bright  line  of  light ;  but  if  they  meet  higgledy- 
piggledy,  one  up  and  the  other  down,  all  in  confusion, 
they  stop  each  other,  and  then  there  is  no  light,  but 
a  line  of  darkness.    And  so  behind  your  piece  of 


Fig.  5. 


s 

1 

1 

'a 

A,  Hole  in  the  shutter. 

B,  Wire  placed  in  the  beam  of  light 

S  S,  Screen  on  which  the  dark  and  light  bands  are  canghL 


wire  you  can  catch  the  waves  on  a  piece  of  paper, 
and  you  will  find  they  make  dark  and  light  lines  one 
side  by  side  with  the  other,  and  by  means  of  these 
bands  it  is  possible  to  find  out  how  large  the  waves 
must  be.    This  question  is  too  difficult  for  us  to  work 


38 


THE  FAIRY-LAND  OF  SCIENCE. 


it  out  here,  but  you  can  see  that  large  waves  will  make 
broader  light  and  dark  bands  than  small  ones  will, 
and  that  in  this  way  the  size  of  the  waves  may  be 
measured. 

And  now  how  large  do  you  think  they  turn  out  to 
be  ?  So  very,  very  tiny  that  about  fifty  thousand 
waves  are  contained  in  a  single  inch  of  space !  I 
have  drawn  on  the  board  the  length  of  an  inch,*  and 
now  I  will  measure  the  same  space  in  the  air  between 
my  finger  and  thumb.  Within  this  space  at  this 
moment  there  are  fifty  thousand  tiny  waves  moving 
up  and  down !  I  promised  you  we  would  find  in 
science  things  as  wonderful  as  in  fairy  tales.  Are  not 
these  tiny  invisible  messengers  coming  incessantly 
from  the  sun  as  wonderful  as  any  fairies }  and  still 
more  so  when,  as  we  shall  see  presently,  they  are  doing 
nearly  all  the  work  of  our  world. 

We  must  next  try  to  realize  how  fast  these  waves 
travel.  You  will  remember  that  an  express  train 
would  take  17 1  years  to  reach  us  from  the  sun;  and 
even  a  cannon-ball  would  take  from  ten  to  thirteen 
years  to  come  that  distance.  Well,  these  tiny  waves 
take  only  seven  minutes  and  a  half  to  come  the  whole 
9 1  millions  of  miles.  The  waves  which  are  hitting  your 
eye  at  this  moment  are  caused  by  a  movement  which 
began  at  the  sun  only  7  J  minutes  ago.  And  remember, 
this  movement  is  going  on  incessantly,  and  these 
waves  are  always  following  one  after  the  other  so 
rapidly  that  they  keep  up  a  perpetual  cannonade 
upon  the  pupil  of  your  eye.  So  fast  do  they  come 
that  about  608  billion  waves  enter  your  eye  in  one 

•  The  width  of  an  inch  may  be  seen  in  Fig.  12,  p.  60. 


SUNBEAMS  AND  THEIR  WORK, 


39 


single  second.*  I  do  not  ask  you  to  remember 
these  figures  ;  I  only  ask  you  to  try  and  picture  to 
yourselves  these  infinitely  tiny  and  active  invisible 
messengers  from  the  sun,  and  to  acknowledge  that 
light  is  a  fairy  thing. 


But  we  do  not  yet  know  all  about  our  sunbeam.  See, 
I  have  here  a  piece  of  glass  with  three  sides,  called  a 
prism.  If  I  put  it  in  the 
sunlight  which  is  streaming 
through  the  window,  what 
happens  ?     Look  !  on  the 


Fig.  6. 


table  there  is  a  line  of  beautiful  colours.  I  can  make 
it  long  or  short,  as  I  turn  the  prism,  but  the  colours 
always  remain  arranged  in  the  same  way.  Here  at 
my  left  hand  is  the  red,  beyond  it  orange,  then  yellow, 
green,  blue,  indigo  or  deep  blue,  and  violet,  shading 
one  into  the  other  all  alone  the  line.    We  have  all 


Fig.  7 


seen  these  colours 
dancing  on  the 
wall  when  the  sun 
has  been  shining 
brightly  on  the 
cut  -  glass  pen- 
dants of  the  chan- 

delier     and    you  ^^^^^^^^^  spectrum  thrown  by  a  prism  on  the 

'  ^  .  wail, 

may  see  them  still  d  E,  Window-shutter.  F,  Round  hole  in  it. 
more  distinctly  if  ABC,  Glass  prism.    M  N,  Wall. 

you  let  a  ray  of  light  into  a  darkened  room,  and 
pass  it  through  the  prism  as  in  the  diagram  (Fig.  7). 

*  Light  travels  at  the  rate  of  192,000  miles,  or  12, 165, 120,000  inches 
in  a  second.  Taking  the  averai^e  number  of  wave-lengths  in  an  inch  af 
50,000,  then  12,165,120,000  X  i;o.ooo  =  608.256,000,000,000. 


40 


THE  FAIRY-LAND  OF  SCIENCE, 


What  are  these  colours  ?  Do  they  come  from  the 
glass  ?  No ;  for  you  will  remember  to  have  seen 
them  in  the  rainbow,  and  in  the  soap-bubble,  and 
even  in  a  drop  of  dew  or  the  scum  on  the  top  of  a 
pond.  This  beautiful  coloured  line  is  only  our  sunbeam 
again,  which  has  been  split  up  into  many  colours  by 
passing  through  the  glass,  as  it  is  in  the  rain-drops  of 
the  rainbow  and  the  bubbles  of  the  scum  of  the 
pond. 

Till  now  we  have  talked  of  the  sunbeam  as  if  it  were 
made  of  only  one  set  of  waves,  but  in  truth  it  is  made 
of  many  sets  of  waves  of  different  sizes,  all  travelling 
along  together  from  the  sun.  These  various  waves 
have  been  measured,  and  we  know  that  the  waves 
which  make  up  red  light  are  larger  and  more  lazy 
than  those  which  make  violet  light,  so  that  there  are 
only  thirty-nine  thousand  red  waves  in  an  inch,  while 
there  are  fifty-seven  thousand  violet  waves  in  the  same 
space. 

How  is  it  then,  that  if  all  these  different  waves, 
making  different  colours,  hit  on  our  eye,  they  do  not 
always  make  us  see  coloured  light }  Because,  unless 
they  are  interfered  with,  they  all  travel  along  together, 
and  you  know  that  all  colours,  mixed  together  in 
proper  proportion,  make  white. 

I  have  here  a  round  piece  of  cardboard,  painted  with 
the  seven  colours  in  succession  several  times  over. 
When  it  is  still  you  can  distinguish  them  all  apart,  but 
when  I  whirl  it  quickly  round — see  ! — the  cardboard 
looks  quite  white,  because  we  see  them  all  so  instan- 
taneously that  they  are  mingled  together.  In  the  same 
way  light  looks  white  to  you,  because  all  the  different 


SUNBEAMS  AND  THEIR  WORK. 


41 


colojred  waves  strike  on  your  eye  at  once.  You 
can  easily  make  one  of  these  cards  for  yourselves, 
only  the  white  will  always  look  dirty,  because  you 
cannot  get  the  colours 
pure. 

Now,  when  the  light 
passes  through  the 
three-sided  glass  or 
prism,  the  waves  are 
spread  out,  and  the 
slow^,  heavy,  red  waves 
lag  behind  and  re- 
main at  the  lower  end 
R  of  the  coloured  line 
on  the  wall  (Fig.  7), 
while  the  rapid  little 
violet  waves  are  bent  more  out  of  their  road  and  run 
to  V  at  the  farther  end  of  the  line  ;  and  the  orange, 
yellow,  green,  blue,  and  indigo  arrange  themselves 
between,  according  to  the  size  of  their  waves. 

And  now  you  are  ver}-  likely  eager  to  ask  why  the 
quick  waves  should  make  us  see  one  colour,  and  the 
slow  waves  another.  This  is  a  very  difficult  question, 
for  we  have  a  great  deal  still  to  learn  about  the  effect 
of  light  on  the  eye.  But  you  can  easily  imagine  that 
colour  is  to  our  eye  much  the  same  as  music  is  to  our 
ear.  You  know  we  can  distinguish  different  notes 
when  the  air-waves  play  slowly  or  quickly  upon  the 
drum  of  the  ear  (as  we  shall  see  in  Lecture  VI.),  and 
somewhat  in  the  same  way  the  tiny  waves  of  the  ether 
play  on  the  retina  or  curtain  at  the  back  of  our  eye, 
and  make  the  nerves  carry  different  messages  to  the 
4 


42 


THK  FAIRY-LAND  OF  SCIENCE. 


brain  :  and  the  colour  we  see  depends  upon  the  number 
of  waves  which  play  upon  the  retina  in  a  second. 

Do  you  think  we  have  now  rightly  answered  the 
question — What  is  a  sunbeam  ?  We  have  seen  that  it 
is  really  a  succession  of  tiny  rapid  waves,  travelling 
from  the  sun  to  us  across  the  invisible  substance  wt 
call  ether,"  and  keeping  up  a  constant  cannonade 
upon  everything  which  comes  in  their  way.  We  have 
also  seen  that,  tiny  as  these  waves  are,  they  can  still 
vary  in  size,  so  that  one  single  sunbeam  is  made  up 
of  myriads  of  different-sized  waves,  which  travel  all 
together  and  make  us  see  white  light;  unless  for  some 
reason  they  are  scattered  apart,  so  that  we  see  them 
separately  as  red,  green,  blue,  or  yellow.  How  they 
are  scattered,  and  many  other  secrets  of  the  sun-waves, 
we  cannot  stop  to  consider  now,  but  must  pass  on  to 
ask — 

What  work  do  the  sunbeams  do  for  us  ? 

They  do  two  things — they  give  us  light  and  heat.  It 
is  by  means  of  them  alone  that  we  see  anything.  When 
the  room  was  dark  you  could  not  distinguish  the  table, 
the  chairs,  or  even  the  walls  of  the  room.  Why  'i 
Because  they  had  no  light-waves  to  send  to  your  eye. 
But  as  the  sunbeams  began  to  pour  in  at  the  window, 
the  waves  played  upon  the  things  in  the  room,  and 
when  they  hit  them  they  bounded  off  them  back  t(j 
your  eye,  as  a  wave  of  the  sea  bounds  back  from  a 
rock  and  strikes  against  a  passing  boat.  Then,  when 
they  fell  upon  your  eye,  they  entered  it  and  excited 
the  retina  and  the  nerves,  and  the  image  of  the  chair 
or  the  table  was  carried  to  your  brain.  Look  around 
at  all  the  things  in  this  room.  Is  it  not  strange  to  think 


SUNBEAMS  AND  THEIR  WORK.  43 


that  each  one  of  them  is  sending  these  invisible  mes- 
sengers straight  to  your  eye  as  you  look  at  it ;  and 
that  you  see  me,  and  distinguish  me  from  the  table, 
entirely  by  the  kind  of  waves  we  each  send  to  you  ? 

Some  substances  send  back  hardly  any  waves  of 
light,  but  let  them  all  pass  through  them,  and  thus  we 
cannot  see  them.  A  pane  of  clear  glass,  for  instance, 
lets  nearly  all  the  light-waves  pass  through  it,  and 
therefore  you  often  cannot  see  that  the  glass  is  there, 
because  no  light-messengers  ':ome  back  to  you  from 
it.  Thus  people  have  sometimes  walked  up  against  a 
glass  door  and  broken  it,  not  seeing  it  was  there. 
Those  substances  are  transparent  which,  for  some 
reason  unknown  to  us,  allow  the  ether  waves  to  pass 
through  therh  without  shaking  the  atoms  of  which  the 
substance  is  made.  In  clear  glass,  for  example,  all 
the  light-waves  pass  through  without  affecting  the 
substance  of  the  glass  ;  while  in  a  white  wall  the 
larger  part  of  the  rays  are  reflected  back  to  your  eye. 
and  those  which  pass  into  the  wall,  by  giving  motion 
to  its  atoms  lose  their  own  vibrations. 

Into  polished  shining  metal  the  waves  hardly  enter 
at  all,  but  are  thrown  back  from  the  surface  ;  and  so  a 
steel  knife  or  a  silver  spoon  are  very  bright,  and  are 
clearly  seen.  Quicksilver  is  put  at  the  back  of  looking- 
glasses  because  it  reflects  so  many  waves.  It  not  only 
sends  back  those  which  come  from  the  sun,  but  those, 
too,  which  come  from  your  face.  So,  when  you  see  your- 
self in  a  looking-glass,  the  sun-waves  have  first  played 
on  your  face  and  bounded  off  from  it  to  the  looking- 
glass  ;  then,  when  they  strike  the  looking-glass,  they 
are  thrown  back  again  on  to  the  retina  of  your  eye,  and 


44  THE  FAIRY-LAND  OF  SCIENCE. 


you  see  your  own  face  by  means  of  the  very  waves  you 
threw  off  from  it  an  instant  before. 

But  the  reflected  Hght-waves  do  more  for  us  than 
this.  They  not  only  make  us  see  things,  but  they 
make  us  see  them  in  different  colours.  What,  you 
will  ask,  is  this  too  the  work  of  the  sunbeams  Cer- 
tainly ;  for  if  the  colour  we  see  depends  on  the  size  of 
the  waves  which  come  back  to  us,  then  we  must  see 
things  coloured  differently  according  to  the  waves  they 
send  back.  For  instance,  imagine  a  sunbeam  playing 
on  a  leaf :  part  of  its  waves  bound  straight  back  from 
it  to  our  eye  and  make  us  see  the  surface  of  the  leaf, 
but  the  rest  go  right  into  the  leaf  itself,  and  there 
some  of  them  are  used  up  and  kept  prisoners.  The 
red,  orange,  yellow,  blue,  and  violet  waves  are  all 
useful  to  the  leaf,  and  it  does  not  let  them  go  again. 
But  it  cannot  absorb  the  green  waves,  and  so  it  throws 
them  back,  and  they  travel  to  your  eye  and  make  you 
see  a  green  colour.  So  when  you  say  a  leaf  is  green, 
you  mean  that  the  leaf  does  not  w^ant  the  green  waves 
of  the  sunbeam,  but  sends  them  back  to  you.  In  the 
same  way  the  scarlet  geranium  rejects  the  red  waves  i 
this  table  sends  back  brown  waves  ;  a  white  tablecloth 
sends  back  nearly  the  whole  of  the  waves,  and  a  black 
coat  scarcely  any.  This  is  why,  when  there  is  very 
little  light  in  the  room,  you  can  see  a  white  tablecloth 
while  you  would  not  be  able  to  distinguish  a  black 
object,  because  the  few  faint  rays  that  are  there,  are 
all  sent  back  to  you  from  a  white  surface. 

Is  it  not  curious  to  think  that  there  is  really  no 
such  thing  as  colour  in  the  leaf,  the  table,  the  coat, 
or  the  geranium  flower,  but  we  see  them  of  different 


SUNBEAMS  AND  THEIR  WORK.  45 


colours  because,  for  some  reason,  they  send  back  only 
certain  coloured  waves  to  our  eye  ? 

Wherever  you  look,  then,  and  whatever  you  see,  all 
the  beautiful  tints,  colours,  lights,  and  shades  around 
you  are  the  work  of  the  tiny  sun-waves. 

Again,  light  does  a  great  deal  of  work  when  it  falls 
upon  plants.  Those  rays  of  light  which  are  caught 
by  the  leaf  are  by  no  means  idle ;  we  shall  see  in 
Lecture  VII.  that  the  leaf  uses  them  to  digest  its  food 
and  make  the  sap  on  which  the  plant  feeds. 

We  all  know  that  a  plant  becomes  pale  and  sickly 
if  it  has  not  sunlight,  and  the  reason  is,  that  without 
these  light-waves  it  cannot  get  food  out  of  the  air,  nor 
make  the  sap  and  juices  which  it  needs.  When  you 
look  at  plants  and  trees  growing  in  the  beautiful 
meadows  ;  at  the  fields  of  corn,  and  at  the  lovely 
landscape,  you  are  looking  on  the  work  of  the  tiny 
waves  of  light,  which  never  rest  all  through  the  day  in 
helping^  to  give  life  to  every  green  thing  that  grows. 

So  far  we  have  spoken  only  of  light ;  but  hold  your 
hand  in  the  sun  and  feel  the  heat  of  the  sunbeams,  and 
then  consider  if  the  waves  of  heat  do  not  do  work 
also.  There  are  many  waves  in  a  sunbeam  which 
move  too  slowly  to  make  us  see  light  when  they  hit 
our  eye,  but  we  can  feel  them  as  heat,  though  we 
cannot  see  them  as  light.  The  simplest  way  of  feeling 
heat-waves  is  to  hold  a  warm  iron  near  your  face.  You 
know  that  no  light  comes  from  it,  yet  you  can  feel  the 
heat-waves  beating  violently  against  your  face  and 
scorching  it.  Now  there  are  many  of  these  dark  heat- 
rays  in  a  sunbeam,  and  it  is  they  which  do  most  of 
the  work  in  the  world 


46  THE  FAIRY-LAND  OF  SCIENCE. 


In  the  first  place,  as  they  come  quivering  to  the 
earth,  it  is  they  which  shake  the  water-drops  apart,  so 
that  these  are  carried  up  in  the  air,  as  we  shall  see  in 
the  next  lecture.    And  then  remember,  it  is  these 
drops,  falling  again  as  rain,  which  make  the  rivers  and 
all  the  moving  water  on  the  earth.    So  also  it  is  the 
heat-waves  which  make  the  air  hot  and  light,  and 
so  cause  it  to  rise  and  make  winds  and  air-currents, 
and  these  again  give  rise  to  ocean-currents.    It  is 
these  dark  rays,  again,  which  strike  upon  the  land  and 
give  it  the  warmth  which  enables  plants  to  grow.  It 
.   is  they  also  which  keep  up  the  warmth  in  our  own 
bodies,  both  by  coming  to  us  directly  from  the  sun, 
and  also  in  a  very  roundabout  way  through  plants. 
You  will  remember  that  plants  use  up  rays  of  light 
and  heat  in  growing ;  then  either  we  eat  the  plants,  or 
animals  eat  the  plants  and  we  eat  the  animals;  and 
when  we  digest  the  food,  that  heat  comes  back  in  our 
bodies,  which  the  plants  first  took  from  the  sunbeam. 
Breathe  upon  your  hand,  and  feel  how  hot  your  breath 
is ;  well,  that  heat  which  you  feel,  was  once  in  a  sun- 
beam, and  has  travelled  from  it  through  the  food  you 
have  eaten,  and  has  now  been  at  work  keeping  up  the 
heat  of  your  body. 

But  there  is  still  another  way  in  which  these  plants 
may  give  out  the  heat-waves  they  have  imprisoned. 
You  will  remember  how  we  learnt  in  the  first  lecture 
•hat  coal  is  made  of  plants,  and  that  the  heat  they 
give  out  is  the  heat  these  plants  once  took  in.  Think 
how  much  work  is  done  by  burning  coals.  Not  only 
are  our  houses  warmed  by  coal  fires  and  lighted  by 
coal  gas,  but  our  steam-engines  and  machinery  work 


SUNBEAMS  AND  THEIR  WORK.  47 


entirely  by  water  which  has  been  turned  into  steam  by 
the  heat  of  coal  and  coke  fires  ;  and  our  steamboats 
travel  all  over  the  world  by  means  of  the  same  power. 
In  the  same  way  the  oil  of  our  lamps  comes  either 
from  olives,  which  grow  on  trees  ;  or  from  coal  and 
the  remains  of  plants  and  animals  in  the  earth.  Even 
our  tallow  candles  are  made  of  mutton  fat,  and  sheep 
eat  grass ;  and  so,  turn  which  way  we  will,  we  find  that 
the  light  and  heat  on  our  earth,  whether  it  comes 
from  fires,  or  candles,  or  lamps,  or  gas,  and  whether 
it  moves  machinery,  or  drives  a  train,  or  propels  a 
ship,  is  equally  the  work  of  the  invisible  waves  of 
ether  coming  from  the  sun,  which  make  what  we  call 
a  sunbeam. 

Lastly,  there  are  still  some  hidden  waves  which  we 
have  not  yet  mentioned,  which  are  not  useful  to  us 
either  as  light  or  heat,  and  yet  they  are  not  idle. 

Before  I  began  this  lecture,  I  put  a  piece  of  paper, 
which  had  been  dipped  in  nitrate  of  silver,  under  a 
piece  of  glass ;  and  between  it  and  the  glass  I  put  a 
piece  of  lace.  Look  what  the  sun  has  been  doing 
while  I  have  been  speaking.  It  has  been  breaking  up 
the  nitrate  of  silver  on  the  paper  and  turning  it  into 
a  deep  brown  substance  ;  only  where  the  threads  of 
the  lace  were,  and  the  sun  could  not  touch  the  nitrate 
of  silver,  there  the  paper  has  remained  light-coloured, 
and  by  this  means  I  have  a  beautiful  impression  of  the 
lace  on  the  paper.  I  will  now  dip  the  impression  into 
water  in  which  some  hyposulphite  of  soda  is  dissolved, 
and  this  will  "fix"  the  picture,  that  is,  prevent  the 
sun  acting  upon  it  any  more  ;  then  the  picture  will 
remain  distinct,  and  I  can  pass  it  round  to  you  all 


♦8 


THE  FAIRY-LAND  OF  SCIENCE. 


Here,  again,  invisible  waves  have  been  at  work,  and 
this  time  neither  as  h'ght  nor  as  heat,  but  as  chemical 
agents,  and  it  is  these  waves  which  give  us  all  our 
beautiful  photographs.  In  any  toyshop  you  can  buy 
this  prepared  paper,  and  set  the  chemical  waves  at 
work  to  make  pictures.    Only  you  must  remember 


Fig.  9. 


Piece  of  lace  photographed  during  the  lecture. 


to  fix  it  in  the  solution  afterwards,  otherwise  the 
chemical  rays  will  goon  working  after  you  have  taken 
the  lace  away,  and  all  the  paper  will  become  brown 
and  your  picture  will  disappear. 

And  now,  tell  me,  may  we  not  honestly  say,  that 
the  invisible  waves  which  make  our  sunbeams,  are 
wonderful  fairy  messengers  as  they  travel  eternally 
and  unceasingly  across  space,  never  resting,  never 
tiring  in  doing  the  work  of  our  world  ?  Little  as  we 
have  been  able  to  learn  about  them  in  one  short  hour, 
do  they  not  seem  to  you  worth  studying  and  worth 
thinking  about,  as  we  look  at  the  beautiful  results  0/ 


SUNBEAMS  AND  THEIR  WORK, 


49 


their  work  ?  The  ancient  Greeks  worshipped  the  sun, 
and  condemned  to  death  one  of  their  greatest  philo- 
sophers, named  Anaxagoras,  because  he  denied  that 
it  was  a  god.  *  We  can  scarcely  wonder  at  this  when 
we  see  what  the  sun  does  for  our  world  ;  but  we  know 
that  it  is  a  huge  globe  made  of  gases  and  fiery  matter, 
and  not  a  god.  We  are  grateful  for  the  sun  instead 
of  to  him,  and  surely  we  shall  look  at  him  with  new 
interest,  now  that  we  can  picture  hig-tiny  messengers, 
the  sunbeams,  flitting  over  all  space,  falling  upon  our 
earth,  giving  us  light  to  see  with,  and  beautiful  colours 
to  enjoy,  warming  the  air  and  the  earth,  making  the 
refreshing  rain,  and,  in  a  word,  filling  the  world  with 
life  and  gladness. 


THE  FAIRY-LAND  OF  SCIENCE. 


LECTURE  III. 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE. 


sit  on  the  bank  of  a  river  in  some  quiet  spot  where 
the  water  was  deep  and  clear,  and  watch  the  fishes 
swimming  lazily  along?  When  I  was  a  child  this 
was  one  of  my  favourite  occupations  in  the  summer- 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE,      5 1 


time  on  the  banks  of  the  Thames,  and  there  was  one 
question  which  often  puzzled  me  greatly,  as  I  watched 
the  minnows  and  gudgeon  gliding  along  through  the 
water.  Why  should  fishes  live  in  something  and  be 
often  buffeted  about  by  waves  and  currents,  while  I 
and  others  lived  on  the  top  of  the  earth  and  not  in 
anything  ?  I  do  not  remember  ever  asking  anyone 
about  this ;  and  if  I  had,  in  those  days  people  did  not 
pay  much  attention  to  children's  questions,  and  pro- 
bably nobody  would  have  told  me,  what  I  now  tell 
you,  that  we  do  live  in  something  quite  as  real  and 
often  quite  as  rough  and  stormy  as  the  water  in  which 
the  fishes  swim.  The  something  in  which  we  live 
is  air,  and  the  reason  that  we  do  not  perceive  it,  is 
that  we  are  in  it,  and  that  it  is  a  gas,  and  invisible  to 
us ;  while  we  are  above  the  water  in  which  the  fishes 
live,  and  it  is  a  liquid  which  our  eyes  can  perceive. 

But  let  us  suppose  for  a  moment  that  a  being,  whose 
eyes  were  so  made  that  he  could  see  gases  as  we  see 
liquids,  was  looking  down  from  a  distance  upon  our 
earth.  He  would  see  an  ocean  of  air,  or  aerial  ocean, 
all  round  the  globe,  with  birds  floating  about  in  it, 
and  people  walking  along  the  bottom,  just  as  we  see 
fish  gliding  along  the  bottom  of  a  river.  It  is  true,  he 
would  never  see  even  the  birds  come  near  to  the  sur- 
face, for  the  highest-flying  bird,  the  condor,  never 
soars  more  than  five  miles  from  the  ground,  and  our 
atmosphere,  as  we  shall  see,  is  at  least  lOO  miles  high 
So  he  would  call  us  all  deep-air  creatures,  just  as 
we  talk  of  deep-sea  animals  ;  and  if  we  can  imagine 
that  he  fished  in  this  air-ocean,  and  could  pull  one  of 
us  out  of  it  into  space,  he  would  find  that  we  should 


52 


THE  FAIRY-LAND  OF  SCIENCE. 


gasp  and  die  just  as  fishes  do  when  pulled  out  of  the 
water. 

He  would  also  observe  very  curious  things  going 
on  in  our  air-ocean ;  he  would  see  large  streams 
and  currents  of  air,  which  we  call  winds,  and  which 
would  appear  to  him  as  ocean-currents  do  to  us,  while 
near  down  to  the  earth  he  would  see  thick  mists 
forming  and  then  disappearing  again,  and  these  would 
be  our  clouds.  From  them  he  would  see  rain,  hail 
and  snow  falling  to  the  earth,  and  from  time  to  time 
bright  flashes  would  shoot  across  the  air-ocean,  which 
would  be  our  lightning.  Nay  even  the  brilliant 
rainbow,  the  northern  aurora  borealis,  and  the  falling 
stars,  which  seem  to  us  so  high  up  in  space,  would  be 
seen  by  him  near  to  our  earth,  and  all  within  the  aerial 
ocean. 

But  as  we  know  of  no  such  being  living  in  space, 
who  can  tell  us  what  takes  place  in  our  invisible  air, 
and  we  cannot  see  it  ourselves,  we  must  try  by  ex- 
periments to  see  it  with  our  imagination,  though  we 
cannot  with  our  eyes. 

First,  then,  can  we  discover  what  air  is  ?  At  one 
time  it  was  thought  that  it  was  a  simple  gas  and  could 
not  be  separated  into  more  than  one  kind.  But  we  are 
now  going  to  make  an  experiment  by  which  it  has 
been  shown  that  air  is  made  of  two  gases  mingled 
together,  and  that  one  of  these  gases,  called  oxygen,  is 
used  up  when  anything  burns,  while  the  other  nitrogen 
is  not  used,  and  only  serves  to  dilute  the  minute 
atoms  of  oxygen.  I  have  here  a  glass  bell-jar,  with  a 
cork  fixed  tightly  in  the  neck,  and  I  place  the  jar  over 
a  pan  of  water,  while  on  the  water  floats  a  plate  with 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE,  53 


a  small  piece  of  phosphorus  upon  it.  You  will  see  that 
by  putting  the  bell-jar  over  the  water,  I  have  shut 
in  a  certain  quantity  of  air,  and  my  object  now  is  to 
use  up  the  oxygen 
out  of  this  air  and 
leave  only  nitro- 
gen behind.  To 
do  this  I  musr 
light  the  piece  of 
phosphorus,  for 
you  will  remem- 
ber it  is  in  burn- 
ing  that   oxygen  phosphorus  burning  under  a  bell -jar  (Roscoe). 

is  used  up.    I  will 

take  the  cork  out,  light  the  phosphorus,  and  cork  up 
the  jar  again.  See  !  as  the  phosphorus  burns  white 
fumes  fill  the  jar.  These  fumes  are  phosphoric  acid, 
which  is  a  substance  made  of  phosphorus  and  oxygen. 
Our  fairy  force  chemical  attraction  "  has  been  at 
work  here,  joining  the  phosphorus  and  the  oxygen  of 
the  air  together. 

Now,  phosphoric  acid  melts  in  water  just  as  sugar 
does,  and  in  a  few  minutes  these  fumes  will  disappear. 
They  are  beginning  to  melt  already,  d^nd  the  water 
from  the  pan  is  rising  up  in  the  bell-jar.  Why  is  this.'^ 
Consider  for  a  moment  what  we  have  done.  First,  the 
jar  was  full  of  air,  that  is,  of  mixed  oxygen  and 
nitrogen  ;  then  the  phosphorus  used  up  the  oxygen, 
making  white  fumes  ;  afterwards,  the  water  sucked  up 
these  fumes  ;  and  so,  in  the  jar  now  nitrogen  is  the  only 
gas  left,  and  the  water  has  risen  up  to  fill  all  the  rest 
of  the  space  that  was  once  tal'en  up  with  the  oxygea 


Fig.  la 


54 


THE  FAIRY- LAND  OF  SCIENCE. 


We  can  easily  prove  that  there  is  no  oxygen  now 
in  the  jar,  I  take  out  the  cork  and  let  a  lighted  taper 
down  into  the  gas.  If  there  were  any  oxygen  the 
taper  would  burn,  but  you  see  it  goes  out  directly, 
proving  that  all  the  oxygen  has  been  used  up  by 
the  phosphorus.  When  this  experiment  is  made  very 
accurately,  we  find  that  for  every  pint  of  oxygen  in  air 
there  are  four  pints  of  nitrogen,  so  that  the  active 
oxygen-atoms  are  scattered  about,  floating  in  the 
sleepy,  inactive  nitrogen. 

It  is  these  oxygen-atoms  which  we  use  up  when  we 
breathe.  If  I  had  put  a  mouse  under  the  bell-jar, 
instead  of  the  phosphorus,  the  water  would  have  risen 
just  the  same,  because  the  mouse  would  have  breathed 
in  the  oxygen  and  used  it  up  in  its  body,  joining  it  to 
carbon  and  making  a  bad  gas,  carbonic  acid,  which 
would  also  melt  in  the  water,  and  when  all  the  oxygen 
was  used,  the  mouse  would  have  died. 

Do  you  see  now  how  foolish  it  is  to  live  in  rooms 
that  are  closely  shut  up,  or  to  hide  your  head  under 
the  bedclothes  when  you  sleep  }  You  use  up  all  the 
oxygen-atoms,  and  then  there  are  none  left  for  you  to 
breathe  ;  and  besides  this,  you  send  out  of  your  mouth 
bad  fumes,  though  you  cannot  see  them,  and  these, 
when  you  breathe  them  in  again,  poison  you  and 
make  you  ill. 

Perhaps  you  will  say,  If  oxygen  is  so  useful,  why  is 
not  the  air  made  entirely  of  it  ?  But  think  for  a 
moment.  If  there  was  such  an  immense  quantity  o{ 
oxygen,  how  fearfully  fast  everything  would  burn  ! 
Our  bodies  would  soon  rise  above  fever  heat  from  the 
quantity  of  oxygen  we  should  take  in,  and  all  fires  and 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE,  55 


lights  would  burn  furiously.  In  fact,  a  flame  once 
lighted  would  spread  so  rapidly  that  no  power  on  earth 
could  stop  it,  and  everything  would  be  destroyed.  So 
the  lazy  nitrogen  is  very  useful  in  keeping  the  oxygen- 
atoms  apart ;  and  we  have  time,  even  when  a  fire  is 
very  large  and  powerful,  to  put  it  out  before  it  has 
drawn  in  more  and  more  oxygen  from  the  surrounding 
air.  Often,  if  you  can  shut  a  fire  into  a  closed  space, 
as  in  a  closely-shut  room  or  the  hold  of  a  ship,  it  will 
go  out,  because  it  has  used  up  all  the  oxygen  in  the 
air. 

So,  you  see,  we  shall  be  right  in  picturing  this  in- 
visible air  all  around  us  as  a  mixture  of  two  gases. 
But  when  we  examine  ordinary  air  very  carefully,  we 
find  small  quantities  of  other  gases  in  it,  besides 
oxygen  and  nitrogen.  First,  there  is  carbonic  acid 
gas.  This  is  the  bad  gas  which  we  give  out  of  our 
mouths  after  we  have  burnt  up  the  oxygen  with  the 
carbon  of  our  bodies  inside  our  lungs ;  and  this  car- 
bonic acid  is  also  given  out  from  everything  that 
burns.  If  only  animals  lived  in  the  world,  this  gas 
would  soon  poison  the  air  ;  but  plants  get  hold  of  it, 
and  in  the  sunshine  they  break  it  up  again,  as  we  shall 
see  in  Lecture  VII.,  and  use  up  the  carbon,  throwing 
the  oxygen  back  into  the  air  for  us  to  use.  Secondly, 
there  are  very  small  quantities  in  the  air  of  ammonia^ 
or  the  gas  which  almost  chokes  you  in  smelling-salts, 
and  which,  when  liquid,  is  commonly  called  spirits 
of  hartshorn."  This  ammonia  is  useful  to  plants,  as 
we  shall  see  by  and  by.  Lastly,  there  is  a  great  deal 
of  water  in  the  air,  floating  about  as  invisible  vapour 
or  water-dust,  and  this  we  shall  speak  of  in  the  next 


THE  FAIRY-LAND  OF  SCIENCE, 


lecture.  Still,  all  these  gases  and  vapours  in  the 
atmosphere  are  in  very  small  quantities,  and  the  bulk 
of  the  air  is  composed  of  oxygen  and  nitrogen. 

Having  now  learned  what  air  is,  the  next  question 
which  presents  itself  is,  Why  does  it  stay  round  ouf 
earth  ?  You  will  remember  we  saw  in  the  first  lecture, 
that  all  the  little  atoms  of  a  gas  are  trying  to  fly  away 
from  each  other,  so  that  if  I  turn  on  this  gas-jet  the 
atoms  soon  leave  it,  and  reach  you  at  the  farther  end 
of  the  room,  and  you  can  smell  the  gas.  Why,  then, 
do  not  all  the  atoms  of  oxygen  and  nitrogen  fly  away 
from  our  earth  into  space,  and  leave  us  without  any  air  ? 

Ah  !  here  you  must  look  for  another  of  our  invisible 
forces.  Have  you  forgotten  our  giant  force,  "  gravita- 
tion," which  draws  things  together  from  a  distance  ? 
This  force  draws  together  the  earth  and  the  atoms  of 
oxygen  and  nitrogen  ;  and  as  the  earth  is  very  big  and 
heavy,  and  the  atoms  of  air  are  light  and  easily 
moved,  they  are  drawn  down  to  the  earth  and  held 
there  by  gravitation.  But  for  all  that,  the  atmosphere 
does  not  leave  off*  trying  to  fly  away  ;  it  is  always 
pressing  upwards  and  outwards  with  all  its  might, 
while  the  earth  is  doing  its  best  to  hold  it  down. 

The  eff'ect  of  this  is,  that  near  the  earth,  where  the 
pull  downward  is  very  strong,  the  air-atoms  are  drawn 
very  closely  together,  because  gravitation  gets  the 
best  in  the  struggle.  But  as  we  get  farther  and  farther 
from  the  earth,  the  pull  downward  becomes  weaker, 
and  then  the  air-atoms  spring  farther  apart,  and  the 
air  becomes  thinner.  Suppose  that  the  lines  in  this 
diagram  represent  layers  of  air.    Near  the  earth  we 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE.  57 

have  to  represent  them  as  lying  closely  together,  but 
as  they  recede  from  the  earth  they  are  also  farther 
apart 

Fig.  II. 


But  the  chief  reason  why  the  air  is  thicker  or 
doiser  nearer  the  earth,  is  because  the  upper  layers 
press  it  down.  If  you  have  a  heap  of  papers  lying 
one  on  the  top  of  the  other,  you  know  that  those  at 
the  bottom  of  the  heap  will  be  more  closely  pressed 
together  than  those  above,  and  just  the  same  is  the 
case  with  the  atoms  of  the  air.  Only  there  is  this 
difference,  if  the  papers  have  lain  for  some  time, 
when  you  take  the  top  ones  off,  the  under  ones  remain 
close  together.  But  it  is  not  so  with  the  air,  because 
air  is  elastic,  and  the  atoms  are  always  trying  to  fly 
apart,  so  that  directly  you  take  away  the  pressure  they 
spring  up  again  as  far  as  they  can. 

I  have  here  an  ordinary  pop-gun.  If  I  push  the 
cork  in  very  tight,  and  then  force  the  piston  slowly 
inwards,  I  can  compress  the  air  a  good  deal.  Now  I 
am  lorcing  the  atoms  nearer  and  nearer  together,  but  at 
5 


58 


THE  FAIRY-LAND  OF  SCIENCE, 


last  they  rebel  so  strongly  against  being  more  crowded 
that  the  cork  cannot  resist  their  pressure.  Out  it 
flies,  and  the  atoms  spread  themselves  out  comfortably 
again  in  the  air  all  around  them.  Now,  just  as  I 
pressed  the  air  together  in  the  pop-gun,  so  the  atmo- 
sphere high  up  above  the  earth  presses  on  the  air 
below  and  keeps  the  atoms  closely  packed  together. 
And  in  this  case  the  atoms  cannot  force  back  the  air 
above  them  as  they  did  the  cork  in  the  pop-gun; 
they  are  obliged  to  submit  to  be  pressed  together. 

Even  a  short  distance  from  the  earth,  however,  at 
the  top  of  a  high  mountain,  the  air  becomes  lighter, 
because  it  has  less  weight  of  atmosphere  above  it,  and 
people  who  go  up  in  balloons  often  have  great  diffi- 
culty in  breathing,  because  the  air  is  so  thin  and  light. 
In  1804  a  Frenchman,  named  Gay-Lussac,  went  up 
four  miles  and  a  half  in  a  balloon,  and  brought  down 
some  air  j  and  he  found  that  it  was  much  less  heavy 
than  the  same  quantity  of  air  taken  close  down  to  the 
earth,  showing  that  it  was  much  thinner,  or  rarer,  as  it 
is  called;*  and  when,  in  1862,  Mr.  Glaisher  and 
Mr.  Coxwell  went  up  five  miles  and  a  half,  Mr. 
Glaisher's  veins  began  to  swell,  and  his  head  grew 
dizzy,  and  he  fainted.  The  air  was  too  thin  for 
him  to  breathe  enough  in  at  a  time,  and  it  did  not 
press  heavily  enough  on  the  drums  of  his  ears  and 
the  veins  of  his  body.  He  would  have  died  if 
Mr.  Coxwell  had  not  quickly  let  off"  some  of  the  gas 
in  the  balloon,  so  that  it  sank  down  into  denser  air. 

•  100  cubic  inches  near  the  earth  weighed  31  grains,  while  the  same 
quantity  taken  at  four  and  a  half  miles  up  in  the  air  weighed  onlv 
12  grains,  or  two-fifths  of  the  weight 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE.  59 


And  now  comes  another  very  interesting  question. 
If  the  air  gets  less  and  less  dense  as  it  is  farther  from 
the  earth,  where  does  it  stop  altogether  ?  We  cannot 
go  up  to  find  out,  because  we  should  die  long  before 
we  reached  the  hmit ;  and  for  a  long  time  we  had  to 
guess  about  how  high  the  atmosphere  probably  was, 
and  it  was  generally  supposed  not  to  be  more  than  fifty 
miles.  But  lately,  some  curious  bodies,  which  we 
should  have  never  suspected  would  be  useful  to  us  in 
this  way,  have  let  us  into  the  secret  of  the  height  of 
the  atmosphere.  Tliese  bodies  are  the  meteors^  or 
falling  stars. 

Most  people,  at  one  time  or  another,  have  seen  what 
looks  like  a  star  shoot  right  across  the  sky,  and  dis- 
appear. On  a  clear  starlight  night  you  may  often  see 
one  or  more  of  these  bright  lights  flash  through  the 
air ;  for  one  falls  on  an  average  in  every  twenty 
minutes,  and  on  the  nights  of  August  9th  and  No- 
vember 13th  there  are  numbers  in  one  part  of  the 
sky.  These  bodies  are  not  really  stars  ;  they  are 
simply  stones  or  lumps  of  metal  flying  through  the 
air,  and  taking  fire  by  clashing  against  the  atoms  of 
oxygen  in  it.  There  are  great  numbers  of  these 
masses  moving  round  and  round  the  sun,  and  when 
our  earth  comes  across  their  path,  as  it  does  espe- 
cially in  August  and  November,  they  dash  with  such 
tremendous  force  through  the  atmosphere  that  they 
grow  white-hot,  and  give  out  light,  and  then  dis- 
appear, melted  into  vapour.  Every  now  and  then 
one  falls  to  the  earth  before  it  is  all  melted  away, 
and  thus  we  learn  that  these  stones  contain  tin,  iroa. 
sulphur,  phosphorus,  and  other  substances. 


6o  THE  FAIRY-LAND  OF  SCIENCE. 


It  is  while  these  bodies  are  burning  that  they  look 
to  us  like  falling  stars,  and  when  we  see  them 
we  know  that  they  must  be  dashing  against  our 
atmosphere.  Now  if  two  people  stand  a  certain 
known  distance,  say  fifty  miles,  apart  on  the  earth, 
and  observe  these  meteors  and  the  direction  in  which 
they  each  see  them  fall,  they  can  calculate  (by  means 
of  the  angle  between  the  two  directions)  how  high  they 
are  above  them  when  they  first  see  them,  and  at  that 
moment  they  must  have  struck  against  the  atmo- 
sphere, and  even  travelled  some  way  through  it,  to 
become  white-hot.  In  this  way  we  have  learnt  that 
meteors  burst  into  light  at  least  loo  miles  above  the 
surface  of  the  earth,  and  so  the  atmosphere  must  be 
more  than  lOO  miles  high. 


Our  next  question  is  as  to  the  weight  of  our  aerial 
ocean.    You  will  easily  understand  that  all  this  air 

weighing  down  upon  the  earth 
must  be  very  heavy,  even  though 
it  grows  lighter  as  it  ascends.  The 
atmosphere  does,  in  fact,  weigh 
down  upon  land  at  the  level  of  the 
sea  as  much  as  if  a  is-pound  weight 
were  put  upon  every  square  inch  oi 
land.  This  little  piece  of  linen 
paper,  which  I  am  holding  up,  mea- 
sures exactly  a  square  inch,  and 
as  it  lies  on  the  table,  it  is  bearing 
a  weight  of  15  lbs.  on  its  surface. 
But  how,  then,  comes  it  that  I  can  lift  it  so  easily  ? 
Why  am  I  not  conscious  of  the  weight? 


A  square  inch  of 
paper,  as  shown  in  the 
lecture. 


-THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE.  6l 


To  umJerstand  this  you  must  give  all  your  attention, 
for  it  is^important  and  at  first  not  very  easy  to  grasp. 
You  must  remember,  in  the  first  place,  that  the  air  is 
heavy  because  it  is  attracted  to  the  earth,  and  in  the 
second  place,  that  since  air  is  elastic  all  the  atoms  of 
;t  are  pushing  upwards  against  this  gravitation.  And 
so,  at  any  point  in  air,  as  for  instance  the  place  where 
the  paper  now  is  as  I  hold  it  up,  I  feel  no  pressure, 
because  exactly  as  much  as  gravitation  is  pulling  the 
air  down,  so  much  elasticity  is  resisting  and  pushing  it 
up.  So  the  pressure  is  equal  upwards,  downwards, 
and  on  all  sides,  and  I  can  move  the  paper  with  equal 
ease  any  way. 

Even  if  I  lay  the  paper  on  the  table  this  is  still 
true,  because  there  is  always  some  air  under  it. 
If,  however,  I  could  get  the  air  quite  away  from  one 
side  of  the  paper,  then  the  pressure  on  the  other 
side  would  show  itself.  I  can  do  this  by  simply 
wetting  the  paper  and  letting  it  fall  on  the  table,  and 
the  water  will  prevent  any  air  from  getting  under  it. 
Now  see !  if  I  try  to  lift  it  by  the  thread  in  the 
middle,  I  have  great  difficulty,  because  the  whole 
15  pounds'  weight  of  the  atmosphere  is  pressing  it 
down.  A  still  better  way  of  making  the  experiment 
is  with  a  piece  of  leather,  such  as  the  boys  often 
amuse  themselves  with  in  the  streets.  This  piece  of 
leather  has  been  well  soaked.  I  drop  it  on  the  floor, 
and  see!  it  requires  all  my  strength  to  pull  it  up.* 

*  In  fastening  the  string  to  the  leather  the  hole  must  be  very  small 
and  the  knot  as  flat  as  possible,  and  it  is  even  well  to  put  a  small  piece 
of  kid  under  the  knot.  When  I  first  made  this  experiment,  not  having 
taken  these  precautions,  it  did  not  succeed  well,  owing  to  air  getting  in 
through  the  hole. 


62'  THE  FAIRY-LAND  OF  SCIENCE. 


Fig-  13. 


Soaked  leather  lifting  a  stone  paper- 
weight. 


I  now  drop  it  on  this  stone  weight,  and  so  heavily  is 
it  pressed  down  upon  it  by  the  atmosphere  that  I  can 

lift  the^weight  with- 
out its  breaking  away 
from  it. 

Have  you  ever  tried 
to  pick  limpets  off  a 
rock  ?  If  so,  you  know 
how  tight  they  cling. 
The  limpet  clings  to 
the  rock  just  in  the 
same  way  as  this  lea- 
ther does  to  the  stone ; 
the  little  animal  ex- 
hausts the  air  inside 
its  shell,  and  then  it  is  pressed  against  the  rock  by 
the  whole  weight  of  the  air  above. 

Perhaps  you  will  wonder  how  it  is  that  if  we  have 
a  weight  of  15  lbs.  pressing  on  every  square  inch 
of  our  bodies,  it  does  not  crush  us.  And,  indeed,  it 
amounts  on  the  whole  to  a  weight  of  about  15  tons 
upon  the  body  of  a  grown  man.  It  would  crush  us  if 
it  were  not  that  there  are  gases  and  fluids  inside  our 
bodies  which  press  outwards  and  balance  the  weight  so 
that  we  do  not  feel  it  at  all. 

This  is  why  Mr.  Glaisher's  veins  swelled  and  he  grew 
giddy  in  thin  air.  The  gases  and  fluids  inside  his 
body  were  pressing  outwards  as  much  as  when  he  was 
below,  but  the  air  outside  did  not  press  so  heavily,  and 
so  all  the  natural  condition  of  his  body  was  disturbed. 

I  hope  we  now  realize  how  heavily  the  air  presse  s 
down  upon  our  earth,  but  it  is  equally  necessary  to 


THE  AERIAL  ocean  IN  WHICH  WE  LIVE,  63 


understand  how,  being  elastic,  it  also  presses  upwards  ; 
and  we  can  prove  this  by  a  simple  experiment  I 
fill  this  tumbler  with  water,  and  keeping  a  piece  of 
card  firmly  pressed  against  it,  I  turn  the  whole  upside- 
down.  When  I  now 
take  my  hand  away 
you  would  naturally 
expect  the  card  to 
fall,  and  the  water  to 
be  spilt.  But  no  !  the 
card  remains  as  if 
glued  to  the  tumbler, 
kept  there  entirely 
by  the  air  pressing 
upwards  against  it.* 
And  now  we  are 


Inverted  tumbler  of  water  with  card  kept 
against  it  by  atmospheric  pressure. 


almost  prepared  to  understand  how  we  can  weigh  the 
invisible  air.  One  more  experiment  first.  I  have 
here  {Fig.  15,  p.  64)  what  is  called  a  U  tube,  be- 
cause it  is  shaped  like  a  large  U.  I  pour  some 
water  in  it  till  it  is  about  half  full,  and  you  will 
notice  that  the  water  stands  at  the  same  height 
in  both  arms  of  the  tube  (A,  Fig.  15),  because  the 
air  presses  on  both  surfaces  alike.  Putting  my 
thumb  on  one  end  I  tilt  the  tube  carefully,  so  as 
to  make  the  water  run  up  to  the  end  of  one  arm,  and 
then  turn  it  back  again  (B,  Fig.  15).  But  the  water 
does  not  now  return  to  its  even  position,  it  remains 

*  Tlie  engraver  has  drawn  the  tumbler  only  half  full  of  water.  The 
experiment  will  succeed  quite  as  well  in  this  way  if  the  tumbler  be 
turned  over  quickly,  so  that  part  of  the  air  escapes  between  the  tumbler 
and  the  card,  and  therefore  the  space  above  the  water  is  occupied  by 
mr  less  dense  than  that  outside. 


64 


THE  FAIRY-LAND  OF  SCIENCE. 


up  in  the  arm  on  which  my  thumb  rests.  Why  is 
this  ?  Because  my  thumb  keeps  back  the  air  from 
pressing  at  that  end,  and  the  whole  weight  of  the 
atmosphere  rests  on  the  water  at  c.  And  so  we 
learn  that  not  only  has  the  atmosphere  real  weight, 
but  we  can  see  the  effects  of  this  weight  by  making 

it  balance  a  co- 
lumn of  water  or 
any  other  liquid. 
In  the  case  of  the 
wetted  leather  we 
felt  the  weight  of 
the  air,  here  we 

A,  Water  in  a  U  tube  under  natural  pressure  effects 
of  air. 

B,  Water  kept  in  one  arm  of  the  tube  by  Now  when  we 
pressure  of  the  air  being  at  the  open  end  only  wish    tO    See  the 

weight  of  the  air 

we  consult  a  barometer^  which  works  really  just  in 
the  same  way  as  the  water  in  this  tube.  An  ordi- 
nary upright  barometer  is  simply  a  straight  tube 
of  glass  filled  with  mercury  or  quicksilver,  and  turned 
upside-down  in  a  small  cup  of  mercury  (see  B, 
Fig.  l6).  The  tube  is  a  little  more  than  30  inches 
long,  and  though  it  is  quite  full  of  mercury  before  it 
is  turned  up  (A),  yet  directly  it  stands  in  the  cup  the 
mercury  falls,  till  there  is  a  height  of  about  30  inches 
between  the  surface  of  the  mercury  in  the  cup  C,  and 
th  at  of  the  mercury  in  the  tube  B.  As  it  falls  it  leaves 
an  empty  space  above  the  mercury  at  B  which  is  called 
a  vacuum^  because  it  has  no  air  in  it.  Now,  the  mercury 
is  under  the  same  conditions  as  the  water  was  in  the 
U  tube,  there  is  no  pressure  upon  it  at  B,  while  there 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE.  65 


is  a  pressure  of  15  lbs.  upon  it  In  the  bowl,  and  there 
fore  it  remains  held  up  in  the  tube. 

But  why  will  it  not  remain  more  than  30  inches 
high  in  the  tube  ?  You  must  remember  it  is  only 
kept  up  in  the  tube  at  all  by  the  air  which  presses  on 


Fig.  16. 


the  mercury  in  the  cup. 
And  that  column  of  mer- 
cury C  B  now  balances 
the  pressure  of  the  air 
outside,  and  presses  down 
on  the  mercury  in  the 
cup  at  its  mouth  just  as 
much  as  the  air  docs  on 
the  rest.  So  this  cup 
and  tube  act  exactly  like 
a  pair  of  scales.  The  air 
outside  is  the  thlnrf  to  be 
weighed  at  one  end  as  it 
presses  on  the  mercury, 
the  column  C  B  answers 
to  the  leaden  weight  at 
the  other  end  which  tells 
you  how  heavy  the  air  is. 
Now  if  the  bore  of  this 
tube  is  made  an  inch 
square,  then  the  30  inches 
of  mercury  in  it  weigh 
exactly  15  lbs.,  and  so  we  know  that  the  weight  of 
the  air  is  15  lbs.  upon  every  square  inch,  but  if  the 
bore  of  the  tube  is  only  half  a  square  inch,  and 
therefore  the  30  inches  of  mercury  only  weigh  y\  lbs,, 
instead  of  15  lbs.,  the  pressure  of  the  atmosphere 


Tube  of  mercury  inverted  in  a 
basin  of  mercury. 


THE  FAIRY-LAND  OF  SCIENCE. 


will  also  be  halved,  because  it  will  only  act  upon 
half  a  square  inch  of  surface,  and  for  this  reason  it 
Fig.  17.  will  make  no  difference  to  the  height 
of  the  mercury  whether  the  tube  be 
broad  or  narrow.  Fig.  17  is  a  picture 
of  the  ordinary  upright  barometer  ;  the 
cup  of  mercury  in  which  the  tube  stands 
is  hidden  inside  the  round  piece  of 
wood  A,  and  just  at  the  bottom  of  this 

Iw  round  is  a  small  hole  B,  through  which 
__  the  air  gets  to  the  cup. 

But  now  suppose  the  atmosphere 
grows  lighter,  as  it  does  when  it  has 
much  damp  in  it.  The  barometer  will 
show  this  at  once,  because  there  will 
be  less  weight  on  the  mercury  in  the 
cup,  therefore  it  will  not  keep  the  mer- 
cury pushed  so  high  up  in  the  tube. 
In  other  words,  the  mercury  in  the 
tube  will  fall. 

Let  us  suppose  that  one  day  the  air 
is  so  much  lighter  that  it  presses  down 
only  with  a  weight  of  14J  lbs.  to  the 
square  inch  instead  of  15  lbs.  Then 
the  mercury  would  fall  to  29  inches, 
because  each  inch  is  equal  to  the 
^'toTneSf-''''  weight  of  half  a  pound.  Now,  when 
A.,  Wood  covering  the  air  is  damp  and  very  full  of  water- 
B!^Hole"rti7<il[^^  vapour  it  is  much  lighter,  and  so  when 
which  air  acts,  the  barometer  falls  we  expect  rain. 
Sometimes,  however,  other  causes  make  the  air  light, 
and  then,  although  the  barometer  is  low,  no  rain  cornea 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE,  67 


Again,  if  the  air  becomes  heavier  the  mercury  is 
pushed  up  above  30  to  31  inches,  and  in  this  way 
we  are  able  to  weigh  the  invisible  air-ocean  all  over 
the  world,  and  tell  when  it  grows  lighter  or  heavier. 
This  then,  is  the  secret  of  the  barometer.  We  cannot 
speak  of  the  thermometer  to-day,  but  I  should  like  to 
warn  you  in  passing  that  it  has  nothing  to  do  with  the 
weight  of  the  air,  but  only  with  heat,  and  acts  in  quite 
a  different  way. 

And  now  we  have  been  so  long  hunting  out,  testing 
and  weighing  our  aerial  ocean,  that  scarcely  any  time 
is  left  us  to  speak  of  its  movements  or  the  pleasant 
breezes  which  it  makes  for  us  in  our  country  walks. 
Did  you  ever  try  to  run  races  on  a  very  windy  day  ? 
Ah !  then  you  feel  the  air  strongly  enough ;  how  it 
beats  against  your  face  and  chest,  and  blows  down 
your  throat  so  as  to  take  your  breath  away ;  and  what 
hard  work  it  is  to  struggle  against  it !  Stop  for  a 
moment  and  rest,  and  ask  yourself,  what  is  the  wind  1 
Why  does  it  blow  sometimes  one  way  and  sometimes 
another,  and  sometimes  not  at  all  1 

Wind  is  nothing  more  than  air  moving  across  the 
surface  of  the  earth,  which  as  it  passes  along  bends 
the  tops  of  the  trees,  beats  against  the  houses,  pushes 
the  ships  along  by  their  sails,  turns  the  windmill, 
carries  off  the  smoke  from  cities,  whistles  through  the 
keyhole,  and  moans  as  it  rushes  down  the  valley. 
What  makes  the  air  restless  1  why  should  it  not 
lie  still  all  round  the  earth 

It  is  restless  because,  as  you  will  remember,  it? 
atoms  are  kept  pressed  together  n^^ar  the  earth  by  the 


68 


THE  FAIRY-LAND  OF  SCIENCE. 


weight  of  the  air  above,  and  they  take  every  oppor- 
tunity, when  they  can  find  more  room,  to  spread  out 
violently  and  rush  into  the  vacant  space,  and  this  rush 
we  call  a  wind. 

Imagine  a  great  number  of  active  schoolboys  all 
crowded  into  a  room  till  they  can  scarcely  move  their 
arms  and  legs  for  the  crush,  and  then  suppose  all  at 
once  a  large  door  is  opened.  Will  they  not  all  come 
tumbling  out  pell-mell,  one  over  the  other,  into  the  hall 
beyond,  so  that  if  you  stood  in  their  way  you  would 
most  likely  be  knocked  down  ?  Well,  just  this  happens 
to  the  air-atoms ;  when  they  find  a  space  before  them 
into  which  they  can  rush,  they  come  on  helter-skelter, 
with  such  force  that  you  have  great  difficulty  in 
standing  against  them,  and  catch  hold  of  something  to 
support  you  for  fear  you  should  be  blown  down. 

But  how  come  they  to  find  any  empty  space  to 
receive  them  }  To  answer  this  we  must  go  back 
again  to  our  little  active  invisible  fairies  the  sunbeams. 
When  the  sun-waves  come  pouring  down  upon  the 
earth  they  pass  through  the  air  almost  without  heating 
it.  But  not  so  with  the  ground  ;  there  they  pass  down 
only  a  short  distance  and  then  are  thrown  back  again. 
And  when  these  sun-waves  come  quivering  back  they 
force  the  atoms  of  the  air  near  the  earth  apart  and 
make  it  lighter ;  so  that  the  air  close  to  the  surface  of  the 
heated  ground  becomes  less  heavy  than  the  air  above  it, 
and  rises  just  as  a  cork  rises  in  water.  You  know  that 
hot  air  rises  in  the  chimney ;  for  if  you  put  a  piece  of 
lighted  paper  on  the  fire  it  is  carried  up  by  the  draught 
of  air,  often  even  before  it  can  ignite.  Now  just  as  the 
hot  air  rises  from  the  fire,  so  it  rises  from  the  heated 


THE  AERIAL  OCEAN  IN  WHICH  IVE  LIVE,  69 


ground  up  into  higher  parts  of  the  atmosphere.  And 
as  it  rises  it  leaves  only  thin  air  behind  it,  and  this 
cannot  resist  the  strong  cold  air  whose  atoms  are 
struggling  and  trying  to  get  free,  and  they  rush  in 
and  fill  the  space. 

One  of  the  simplest  examples  of  wind  is  to  be 
found  at  the  seaside.  There  in  the  daytime  the  land 
gets  hot  under  the  sunshine,  and  heats  the  air,  making 
it  grow  light  and  rise.  Meanwhile  the  sunshine  on 
the  water  goes  down  deeper,  and  so  does  not  send 
back  so  many  heat-waves  into  the  air ;  consequently 
the  air  on  the  top  of  the  water  is  cooler  and  heavier, 
and  it  rushes  in  from  over  the  sea  to  fill  up  the  space 
on  the  shore  left  by  the  warm  air  as  it  rises.  This  is 
why  the  seaside  is  so  pleasant  in  hot  weather.  During 
the  daytime  a  light  sea-breeze  nearly  always  sets  in 
from  the  sea  to  the  land. 

When  night  comes,  however,  then  the  land  loses 
its  heat  very  quickly,  because  it  has  not  stored  it 
up  and  the  land-air  grows  cold  ;  but  the  sea,  which 
has  been  hoarding  the  sun-waves  down  in  its  depths, 
now  gives  them  up  to  the  atmosphere  above  it,  and 
the  sea-air  becomes  warm  and  rises.  For  this  reason 
it  is  now  the  turn  of  the  cold  air  from  the  land  to 
spread  over  the  sea,  and  you  have  a  land-breeze  blowing 
off  the  shore. 

Again,  the  reason  why  there  are  such  steady  winds, 
called  the  trade  winds,  blowing  towards  the  equator, 
is  that  the  sun  is  very  hot  at  the  equator,  and  hot  air 
is  always  rising  there  and  making  room  for  colder  air 
to  rush  in.  We  have  not  time  to  travel  farther  with 
the  moving  air,  though  its  journeys  are  extremely 


70  THE  FAIRY-LAND  OF  SCIENCE, 

interesting  ;  but  if,  when  you  read  about  the  trade  and 
other  winds,  you  will  always  picture  to  yourselves 
warm  air  made  light  by  heat  rising  up  into  space  and 
cold  air  expanding  and  rushing  in  to  fill  its  place,  I 
can  promise  you  that  you  will  not  find  the  study  of 
aerial  currents  so  dry  as  many  people  imagine  it 
to  be. 

We  are  now  able  to  form  some  picture  of  our  aerial 
ocean.  We  can  imagine  the  active  atoms  of  oxygen 
floating  in  the  sluggish  nitrogen,  and  being  used  up  in 
every  candle-flame,  gas-jet  and  fire,  and  in  the  breath 
of  all  living  beings  ;  and  coming  Qjyit  again  tied  fast  to 
atoms  of  carbon  and  making  carbonic  acid.  Then  we 
can  turn  to  trees  and  plants,  and  see  them  tearing  these 
two  apart  again,  holding  the  carbon  fast  and  sending 
the  invisible  atoms  of  oxygen  bounding  back  again 
into  the  air,  ready  to  recommence  work.  We  can 
picture  all  these  air-atoms,  whether  of  oxygen  or 
nitrogen,  packed  close  together  on  the  surface  of  the 
earth,  and  lying  gradually  farther  and  farther  apart,  as 
they  have  less  weight  above  them,  till  they  become  so 
scattered  that  we  can  only  detect  them  as  they  rub 
against  the  flying  meteors  which  flash  into  light.  We 
can  feel  this  great  weight  of  air  pressing  the  limpet  on 
to  the  rock  ;  and  we  can  see  it  pressing  up  the  mercury 
in  the  barometer  and  so  enabling  us  to  measure  its 
weight.  Lastly,  every  breath  of  wind  that  blows  past 
us  tells  us  how  this  aerial  ocean  is  always  moving  to 
and  fro  on  the  face  of  the  earth  ;  and  if  we  think  for  a 
moment  how  much  bad  air  and  bad  matter  it  must 
carry  away,  as  it  goes  froni  crowded  cities  to  be 


THE  AERIAL  OCEAN  IN  WHICH  WE  LIVE.     7 1 


purified  in  the  country,  we  can  see  how,  in  even  this 
one  way  alone,  it  is  a  great  blessing  to  us. 

Yet  even  now  we  have  not  mentioned  many  of  the 
b?!auties  of  our  atmosphere.  It  is  the  tiny  particles 
floating  in  the  air  which  scatter  the  light  of  the  sun 
so  that  it  spreads  over  the  whole  country  and  into 
shady  places.  The  sun's  rays  always  travel  straight 
forward  ;  and  in  the  moon,  where  there  is  no  atmo- 
sphere, there  is  no  light  anywhere  except  just  where 
the  rays  fall.  But  on  our  earth  the  sun-waves  hit 
against  the  myriads  of  particles  in  the  air  and  glide 
off  them  into  the  corners  of  the  room  or  the  recesses 
of  a  shady  lane,  and  so  we  have  light  spread  before 
us  wherever  we  walk  in  the  daytime,  instead  of 
those  deep  black  shadows  which  we  can  see  through 
a  telescope  on  the  face  of  the  moon. 

Again,  it  is  electricity  playing  in  the  air-atoms 
which  gives  us  the  beautiful  lightning  and  the  grand 
aurora  borealis,  and  even  the  twinkling  of  the  stars  is 
produced  entirely  by  minute  changes  in  the  air.  If  it 
were  not  for  our  aerial  ocean  the  stars  would  stare 
at  us  sternly,  instead  of  smiling  with  the  pleasant 
twinkle-twinkle  which  we'  have  all  learned  to  love  as 
little  children. 

All  these  questions,  however,  we  must  leave  for  the 
present ;  only  I  hope  you  will  be  eager  to  read  about 
them  wherever  you  can,  and  open  your  eyes  to  learn 
their  secrets.  For  the  present  we  must  be  content  if 
we  can  even  picture  this  wonderful  ocean  of  gas 
spread  round  our  earth,  and  some  of  the  work  it  does 
for  us. 

We  said  in  the  last  lecture  that  without  the  sun- 


72 


THE  FAIRV-LAND  OF  SCIENCE. 


beams  the  earth  would  be  cold,  dark,  and  frost-ridden. 
With  sunbeams,  but  without  air,  it  would  indeed  have 
burning  heat,  side  by  side  with  darkness  and  ice,  but 
it  could  have  no  soft  light.  Our  planet  might  look 
beautiful  to  others,  as  the  moon  does  to  us,  but  it 
C^^uld  have  comparatively  few  beauties  of  its  own. 
With  the  sunbeams  and  the  air,  we  see  it  has  much 
to  make  it  beautiful.  But  a  third  worker  is  wanted 
before  our  planet  can  revel  in  activity  and  life.  This 
worker  is  water  ;  and  in  the  next  lecture  we  shall 
learn  something  of  the  beauty  and  the  usefulness  of 
the    drops  of  water  "  on  their  travels. 


A  DROP  OF  WA  TER. 


73 


LECTURE  IV. 


A  DROr  OF  WATER  ON  ITS  TRAVELa 


74 


THE  FAIRY-LAND  OF  SCIENCE. 


a  small  glistening  drop  out  of  the  body  of  water 
below,  and  hold  it  before  you.  Tell  me,  have  you 
any  idea  where  this  drop  has  been  ?  what  changes  it 
has  undergone,  and  what  work  it  has  been  doing 
during  all  the  long  ages  that  water  has  lain  on  the 
face  of  the  earth  ?  It  is  a  drop  now,  but  it  was  not 
so  before  I  lifted  it  out  of  the  basin  ;  then  it  was 
part  of  a  sheet  of  water,  and  will  be  so  again  if  I  let 
it  fall.  Again,  if  I  were  to  put  this  basin  on  the  stove 
till  all  the  water  had  boiled  away,  where  would  my 
drop  be  then  ?  Where  would  it  go  ?  What  forms 
will  it  take  before  it  reappears  in  the  rain-cloud,  the 
river,  or  the  sparkling  dew  ? 

These  are  questions  we  are  going  to  try  to  answer 
to-day;  and  first,  before  we  can  in  the  least  under- 
stand how  water  travels,  we  must  call  to  mind  what 
we  have  learnt  about  the  sunbeams  and  the  air.  We 
must  have  clearly  pictured  in  our  imagination  those 
countless  sun-waves  which  are  for  ever  crossing  space, 
and  especially  those  larger  and  slower  undulations,  the 
dark  heat-waves ;  for  it  is  these,  you  will  remember, 
which  force  the  air- atoms  apart  and  make  the  air 
light,  and  it  is  also  these  which  are  mo^t  busy  in 
sending  water  on  its  travels.  But  not  these  alone. 
The  sun-waves  might  shake  the  water-drops  as  much 
as  they  liked,  and  turn  them  into  invisible  vapour,  but 
they  could  not  carry  them  over  the  earth  if  it  were  not 
for  the  winds  and  currents  of  that  aerial  ocean  whicli 
bears  the  vapour  on  its  bosom,  and  wafts  it  to  different 
regions  of  the  world. 

Let  us  try  to  understand  how  these  two  invisible 
workers,  the  sun-waves  and  the  air,  deal  with  the  drops 


A  DROP  OF  WATER. 


^  75 


of  water.    I  have  here  a  kettle  (Fig.  i8,  p.  76)  boiling 
over  a  spirit-lamp,  and  I  want  you  to  follow  minutely 
what  is  going  on  in  it.  First,  in  the  flame  of  the  lamp, 
atoms  of  the  spirit  drawn  up  from  below  are  clashing 
with  the  oxygen-atoms  in  the  air.    This,  as  you  know, 
causes  heat-waves  and  light-waves  to  move  rapidly 
all  round  the  lamp.    The  light-waves  cannot  pass 
through  the  kettle,  but  the  heat-waves  can,  and  as 
they  enter  the  water  inside  they  agitate  it  violently. 
Quickly,  and  still  more  quickly,  the  particles  of  water 
near  the  bottom  of  the  kettle  move  to  and  fro  and  are 
shaken  apart  ;  and  as  they  become  light  they  rise 
through  the  colder  water,  letting  another  layer  come 
down  to  be  heated  in  its  turn.    The  motion  grows 
more  and  more  violent,  making  the  water  hotter  and 
hotter,  till  at  last  the  particles  of  which  it  is  com- 
posed fly  asunder,  and  escape  as  invisible  vapour. 
If  this  kettle  were  transparent  you  would  not  see  any 
steam  above  the  water,  because  it  is  in  the  form  of  an 
invisible  gas.    But  as  the  steam  comes  out  of  the 
mouth  of  the  kettle  you  see  a  cloud.    Why  is  this  } 
Because  the  vapour  is  chilled  by  coming  out  into  the 
cold  air,  and  its  particles  are  drawn  together  again 
into  tiny,  tiny  drops  of  water,  to  which  Dr.  Tyndall  has 
given  the  suggestive  name  of  water-dust.    If  you 
hold  a  plate  over  the  steam  you  can  catch  these  tiny 
drops,  though  they  will  run  into  one  another  almost 
as  you  are  catching  them. 

The  clouds  you  see  floating  in  the  sky  are  made  of 
exactly  the  same  kind  of  water-dust  as  the  cloud  from 
the  kettle,  and  I  wish  to  show  you  that  this  is  also  really 
the  same  as  the  invisible  steam  within  the  kettle.  I 


76 


THE  FAIRY-LAND  OF  SCIENCE. 


will  do  so  by  an  experiment  suggested  by  Dr.  Tyndall 
Here  is  another  spirit-lamp,  which  I  will  hold  under 
the  cloud  of  steam — see !  the  cloud  disappears  !  As 


soon  as  the  water-dust  is  heated  the  heat-waves 
scatter  it  again  into  invisible  particles,  which  float 
away  into  the  room.  Even  without  the  spirit-lamp, 
you  can  convince  yourself  that  water -vapour  may  be 
invisible  ;  for  close  to  the  mouth  of  the  kettle  you  will 
see  a  short  blank  space  before  the  cloud  begins.  In 
this  space  there  must  be  steam,  but  it  is  still  so  hot 
that  you  cannot  see  it ;  and  this  proves  that  heat- 
waves can  so  shake  water  apart  as  to  carry  it  away 
invisibly  right  before  your  eyes. 

Now,  although  we  never  see  any  water  travelling 
from  our  earth  up  into  the  skies,  we  know  that  it  goes 
there,  for  it  comes  down  again  in  rain,  and  so  it  must 
go  up  invisibly.  But  where  does  the  heat  come  from 
which  makes  this  water  invisible }  Not  from  below, 
as  in  the  case  of  the  kettle,  but  from  above,  pouring 
down  from  the  sun.  Wherever  the  sun-waves  touch 
the  rivers,  ponds,  lakes,  seas,  or  fields  of  ice  and  snow 


Fig.  1 8. 


A  DROP  OF  WATER. 


77 


upon  our  earth,  they  carry  off  invisible  water-vapour. 
They  dart  down  through  the  top  layers  of  the  water, 
and  shake  the  water-particles  forcibly  apart  ;  and 
in  this  case  the  drops  fly  asunder  more  easily  and 
before  they  are  so  hot,  because  they  are  not  kept 
down  by  a  great  weight  of  water  above,  as  in  the 
kettle,  but  find  plenty  of  room  to  spread  themselves 
out  in  the  gaps  between  the  air-atoms  of  the  atmo- 
sphere. 

Can  you  imagine  these  water-particles,  just  above 
any  pond  or  lake,  rising  up  and  getting  entangled 
among  the  air-atoms  ?  They  are  very  light,  much 
lighter  than  the  atmosphere ;  and  so,  when  a  great 
many  of  them  are  spread  about  in  the  air  which  lies 
just  over  the  pond,  they  make  it  much  lighter  than 
the  layer  of  air  above,  and  so  help  it  to  rise,  while 
the  heavier  layer  of  air  comes  down  ready  to  take 
up  more  vapour. 

In  this  way  the  sun-waves  and  the  air  carry  off 
water  every  day,  and  all  day  long,  from  the  top  of 
lakes,  rivers,  pools,  springs,  and  seas,  and  even  from 
the  surface  of  ice  and  snow.  Without  any  fuss  or 
noise  or  sign  of  any  kind,  the  water  of  our  earth 
is  being  drawn  up  invisibly  into  the  sky. 

It  has  been  calculated  that  in  the  Indian  Ocean 
three-quarters  of  an  inch  of  water  is  carried  off  from 
the  surface  of  the  sea  in  one  day  and  night ;  so  that 
as  much  as  22  feet,  or  a  depth  of  water  about  twice 
the  height  of  an  ordinary  room,  is  silently  and  in- 
visibly lifted  up  from  the  whole  surface  of  the  ocean 
in  one  year.  It  is  true  this  is  one  of  the  hottest  parts 
^f  the  earth,  where  the  sun-waves  are  most  active ; 


78 


THE  FAIRY-LAND  OF  SCIENCE. 


but  even  in  our  own  country  many  feet  of  water  are 
drawn  up  in  the  summer-time. 

What,  then,  becomes  of  all  this  water  ?  Let  us  follow 
it  as  it  struggles  upwards  to  the  sky.    We  see  it  in 
our  imagination  first  carrying  layer  after  layer  of  air 
up  with  it  from  the  sea  till  it  rises  far  above  our  heads 
and  above  the  highest  mountains.    But  now,  call  to 
mind  what  happens  to  the  air  as  it  recedes  from  the 
earth.    Do  you  not  remember  that  the  air-atoms  are 
always  trying  to  fly  apart,  and  are  only  kept  pressed 
together  by  the  weight  of  air  above  them  t    Well,  as 
this  water-laden  air  rises  up,  its  particles,  no  longer  so 
much  pressed  together,  begin  to  separate,  and  as  all 
work  requires  an  expenditure  of  heat,  the  air  becomes 
colder,  and  then  you  know  at  once  what  must  happen 
to  the  invisible  vapour, — it  will  form  into  tiny  water- 
drops,  like  the  steam  from  the  kettle.    And  so,  as  the 
air  rises  and  becomes  colder,  the  vapour  gathers  into 
visible  masses,  and  we  can  see  it  hanging  in  the  sky, 
and  call  it  clouds.  When  these  clouds  are  highest  they 
are  about  ten  miles  from  the  earth,  but  when  they  are 
made  of  heavy  drops  and  hang  low  down,  they  some- 
times come  within  a  mile  of  the  ground. 

Look  up  at  the  clouds  as  you  go  home,  and  think 
that  the  water  of  which  they  are  rriade  has  all  been 
drawn  up  invisibly  through  the  air.  Not,  however, 
necessarily  here  in  London,  for  we  have  already  seen 
that  air  travels  as  wind  all  over  the  world,  rushing  in 
to  fill  spaces  made  by  rising  air  wherever  they  occur, 
and  so  these  clouds  may  be  made  of  vapour  collected 
in  the  Mediterranean,  or  in  the  Gulf  of  Mexico  off 
the  coast  of  America,  or  even,  if  the  wind  is  from 


A  DROP  OF  WATER. 


79 


the  north,  of  chilly  particles  gathered  from  the  surface 
of  Greenland  ice  and  snow,  and  brought  here  by  the 
moving  currents  of  air.  Only,  of  one  thing  we  may 
be  sure,  that  they  come  from  the  water  of  our  earth. 

Sometimes,  if  the  air  is  warm,  these  water-particles 
may  travel  a  long  way  without  ever  forming  into 
clouds  ;  and  on  a  hot,  cloudless  day  the  air  is  often 
very  full  of  invisible  vapour.  Then,  if  a  cold  wind 
comes  sweeping  along,  high  up  in  the  sky,  and  chills 
this  vapour,  it  forms  into  great  bodies  of  water-dust 
clouds,  and  the  sky  is  overcast.     At  other  times 


Fig.  19. 


Clouds  formed  by  ascending  vapour  as  it  enters  cold  spaces  in  the 

atmosphere. 

clouds  hang  lazily  in  a  bright  sky,  and  these  show  us 
that  just  where  they  are  (as  in  Fig.  19)  the  air  is  cold 
and  turns  the  invisible  vapour  rising  from  the  ground 
into  visible  water-dust,  so  that  exactly  in  those  spaces 
we  see  it  as  clouds.  Such  clouds  form  often  on  a 
warm,  still  summer's  day,  and  they  are  shaped  like 
masses  of  wool,  ending  in  a  straight  line  below.  They 
are  not  merely  hanging  in  the  sky,  they  are  really 
resting  upon  a  tall  column  of  invisible  vapour  which 
stretches  right  up  from  the  earth  ;  and  that  straight 


8o  THE  FAIRY-LAND  OF  SCIENCE. 

line  under  the  clouds  marks  the  place  where  the  air 
becomes  cold  enough  to  turn  this  invisible  vapour  into 
visible  drops  of  water. 

And  now,  suppose  that  while  these  or  any  other 
kind  of  clouds  are  overhead,  there  comes  along  eithei 
a  very  cold  wind,  or  a  wind  full  of  vapour.  As  it 
passes  through  the  clouds,  it  makes  them  very  full  of 
water,  for,  if  it  chills  them,  it  makes  the  water-dust 
draw  more  closely  together  ;  or,  if  it  brings  a  new  load 
of  water- dust,  the  air  is  fuller  than  it  can  hold.  In 
either  case  a  number  of  water-particles  are  set  free, 
and  our  fairy  force  "cohesion'*  seizes  upon  them  at 
once  and  forms  them  into  large  water-drops.  Then 
they  are  much  heavier  than  the  air,  and  so  they  can 
float  no  longer,  but  down  they  come  to  the  earth  in  a 
shower  of  rain. 

There  are  other  ways  in  which  the  air  may  be 
chilled,  and  rain  made  to  fall,  as,  for  example,  when 
a  wind  laden  with  moisture  strikes  against  the  cold 
tops  of  mountains.  Thus  the  Khasia  Hills  in  India, 
which  face  the  Bay  of  Bengal,  chill  the  air  which 
crosses  them  on  its  way  from  the  Indian  Ocean.  The 
wet  winds  are  driven  up  the  sides  of  the  hills,  the  air 
expands,  and  the  vapour  is  chilled,  and  forming  into 
drops,  falls  in  torrents  of  rain.  Sir  J.  Hooker  tells  us 
that  as  much  as  500  inches  of  rain  fell  in  these  hills 
in  nine  months.  That  is  to  say,  if  you  could  measure 
off  all  the  ground  over  which  the  rain  fell,  and  spread 
the  whole  nine  months'  rain  over  it,  it  would  make  a 
lake  500  inches,  or  more  than  40  feet  deep !  You  will 
not  be  surprised  that  the  country  on  the  other  side  of 
these  hills  gets  hardly  any  rain,  for  all  the  water  has 


A  DROP  OF  WATER. 


81 


been  taken  out  of  the  air  before  it  comes  there.  Again 
for  example  in  England,  the  wind  comes  to  Cumber- 
land and  Westmorland  over  the  Atlantic,  full  of 
vapour,  and  as  it  strikes  against  the  Pennine  Hills  it 
shakes  off  its  watery  load  ;  so  that  the  lake  district  is 
the  most  rainy  in  England,  with  the  exception  perhaps 
of  Wales,  where  the  high  mountains  have  the  same 
effect. 

In  this  way,  from  different  causes,  the  water  of 
which  the  sun  has  robbed  our  rivers  and  seas,  comes 
back  to  us,  after  it  has  travelled  to  various  part^  of 
the  world,  floating  on  the  bosom  of  the  air.  But  it 
does  not  always  fall  straight  back  into  the  rivers  and 
seas  again,  a  large  part  of  it  falls  on  the  land,  and  has 
to  trickle  down  slopes  and  into  the  earth,  in  order  to 
get  back  to  its  natural  home,  and  it  is  often  caught  on 
its  way  before  it  can  reach  the  great  waters. 

Go  to  any  piece  of  ground  which  is  left  wild  and 
untouched,  you  will  find  it  covered  with  grass,  weeds, 
and  other  plants  ;  if  you  dig  up  a  small  plot  you  will 
find  innumerable  tiny  roots  creeping  through  the 
ground  in  every  direction.  Each  of  these  roots  has 
a  sponge-like  mouth  by  which  the  plant  takes  up 
water.  Now,  imagine  rain-drops  falling  on  this  plot 
of  ground  and  sinking  into  the  earth.  On  every  side 
they  will  find  rootlets  thirsting  to  drink  them  in,  and 
they  will  be  sucked  up  as  if  by  tiny  sponges,  and 
drawn  into  the  plants,  and  up  the  stems  to  the  leaves. 
Here,  as  we  shall  see  in  Lecture  VH.,  they  are  worked 
up  into  food  for  the  plant,  and  only  if  the  leaf  has 
9         more  water  than  it  needs,  some  drops  may  escape  at 


82  THE  FAIRY-LAND  OF  SCIENCE. 


the  tiny  openings  under  the  leaf,  and  be  drawn  up 
again  by  the  sun-waves  as  invisible  vapour  into  the 
air 

Again,  much  of  the  rain  falls  on  hard  rock  and 
stone,  where  it  cannot  sink  in,  and  then  it  lies  in  pools 
till  it  is  shaken  apart  again  into  vapour  and  carried 
off  in  the  air.  Nor  is  it  idle  here,  even  before  it  is 
carried  up  to  make  clouds.  We  have  to  thank  this 
invisible  vapour  in  the  air  for  protecting  us  from  the 
burning  heat  of  the  sun  by  day  and  intolerable  frost 
by  night. 

Let  us  for  a  moment  imagine  that  we  can  see  all 
that  we  know  exists  between  us  and  the  sun.  First, 
we  have  the  fine  ether  across  which  the  sunbeams 
travel,  beating  down  upon  our  earth  with  immense 
force,  so  that  in  the  sandy  desert  they  are  like  a 
burning  fire.  Then  we  have  the  coarser  atmosphere  of 
oxygen  and  nitrogen  atoms  hanging  in  this  ether,  and 
bending  the  minute  sun-waves  out  of  their  direct  path. 
But  they  do  very  little  to  hinder  them  on  their  way, 
and  this  is  why  in  very  dry  countries  the  sun*s  heat  is 
so  intense.  The  rays  beat  down  mercilessly,  and 
nothing  opposes  them.  Lastly,  in  damp  countries  we 
have  the  larger  but  still  invisible  particles  of  vapour 
hanging  about  among  the  air-atoms.  Now,  these 
watery  particles,  although  they  are  very  few  (only 
about  one  twenty-fifth  part  of  the  whole  atmosphere), 
do  hinder  the  sun-waves.  For  they  are  very  greedy 
of  heat,  and  though  the  light-waves  pass  easily  through 
them;  they  catch  the  heat-waves  and  use  them  to  help 
themselves  to  expand.  And  so,  when  there  is  invisible 
vapour  in  the  air,  the  sunbeams  come  to  us  deprived 


A  DROP  OF  WATER. 


8.3 


of  some  of  their  heat-wa\'es,  and  we  can  remain  in  the 
sunshine  without  sufferins^  from  the  heat. 

This  is  how  the  water-vapour  shields  us  by  day, 
but  by  night  it  is  still  more  useful.  During  the  day 
our  earth  and  the  air  near  it  have  been  storing  up  the 
heat  which  has  been  poured  down  on  them,  and  at 
night,  when  the  sun  goes  down,  all  this  heat  begins  to 
escape  again.  Now,  if  there  were  no  vapour  in  the  air, 
this  heat  would  rush  back  into  space  so  rapidly  that 
the  ground  would  become  cold  and  frozen  even  on  a 
summer's  night,  and  all  but  the  most  hardy  plants 
would  die.  But  the  vapour  which  formed  a  vei) 
against  the  sun  in  the  day,  now  forms  a  still  more 
powerful  veil  against  the  escape  of  the  heat  by  night. 
It  shuts  in  the  heat-waves,  and  only  allows  them  to 
make  their  way  slowly  upwards  from  the  earth — thus 
producing  for  us  the  soft,  balmy  nights  of  summer 
and  preventing  all  life  being  destroyed  in  the  winter. 

Perhaps  you  would  scarcely  imagine  at  first  that  it 
is  this  screen  of  vapour  which  determines  whether  or 
not  we  shall  have  dew  upon  the  ground.  Have  you 
ever  thought  why  dew  forms,  or  what  power  has 
been  at  work  scattering  the  sparkling  drops  upon  the 
grass }  Picture  to  yourself  that  it  has  been  a  very 
hot  summer  s  day,  and  the  ground  and  the  grass  have 
been  well  warmed,  and  that  the  sun  goes  down  in  a 
clear  sky  without  any  clouds.  At  once  the  heat-waves 
which  have  been  stored  up  in  the  ground,  bound  back 
into  the  air,  and  here  some  are  greedily  absorbed  by 
the  vapour,  while  others  make  their  way  slowly  up- 
wards. The  grass,  especially,  gives  out  these  heat- 
waves very  quickly,  because  the  blades,  being  very 


84 


THE  FAIRY-LAND  OF  SCIENCE. 


thin,  are  almost  all  surface.  In  consequence  of  this 
they  part  with  their  heat  more  quickly  than  they  can 
draw  it  up  from  the  ground,  and  become  cold.  Now, 
the  air  lying  just  above  the  grass  is  full  of  invisible 
vapour,  and  the  cold  of  the  blades,  as  it  touches  them, 
chills  the  water-particles,  and  they  are  no  longer  able 
to  hold  apart,  but  are  drawn  together  into  drops  on  the 
surface  of  the  leaves. 

We  can  easily  make  artificial  dew  for  ourselves.  I 
have  here  a  bottle  of  ice  which  has  been  kept  outside 
the  window.  When  I  bring  it  into  the  warm  room  a 
mist  forms  rapidly  outside  the  bottle.  This  mist  is 
composed  of  water-drops,  drawn  out  of  the  air  of  the 
room,  because  the  cold  glass  chilled  the  air  all  round 
it,  so  that  it  gave  up  its  invisible  water  to  form  dew- 
drops.  Just  in  this  same  way  the  cold  blades  of  grass 
chill  the  air  lying  above  them,  and  steal  its  vapour. 

But  try  the  experiment,  some  night  when  a  heavy 
dew  is  expected,  of  spreading  a  thin  piece  of  muslin 
over  some  part  of  the  grass,  supporting  it  at  the  four 
corners  with  pieces  of  stick  so  that  it  forms  an 
awning.  Though  there  may  be  plenty  of  dew  on  the 
grass  all  round,  yet  under  this  awning  you  will  find 
scarcely  any.  The  reason  of  this  is  that  the  muslin 
checks  the  heat-waves  as  they  rise  from  the  grass, 
and  so  the  grass-blades  are  not  chilled  enough  to 
draw  together  the  water-drops  on  their  surface.  If 
you  walk  out  early  in  the  summer  mornings  and  look 
at  the  fine  cobwebs  flung  across  the  hedges,  you 
will  see  plenty  of  drops  on  the  cobwebs  themselves 
sparkling  like  diamonds ;  but  underneath  on  the 
leaves  there  will  be  none,  for  even  the  delicate  cobweb 


A  DROP  OF  WA  TER. 


85 


has  been  strong  enough  to  shut  in  the  heat-waves  and 
keep  the  leaves  warm. 

Again,  if  you  walk  off  the  grass  on  to  the  gravel 
path,  you  find  no  dew  there.  Why  is  this  ?  Because 
the  stones  of  the  gravel  can  draw  up  heat  from  the 
earth  below  as  fast  as  they  give  it  out,  and  so  they 
are  never  cold  enough  to  chill  the  air  which  touches 
them.  On  a  cloudy  night  also  you  will  often  find 
little  or  no  dew  even  on  the  grass.  The  reason  of 
this  is  that  the  clouds  give  back  heat  to  the  earth, 
and  so  the  grass  does  not  become  chilled  enough  to 
draw  the  water-drops  together  on  its  surface.  But 
after  a  hot,  dry  day,  when  the  plants  are  thirsty  and 
there  is  little  hope  of  rain  to  refresh  them,  then  they 
are  able  in  the  evening  to  draw  the  little  drops  from 
the  air  and  drink  them  in  before  the  rising  sun  comes 
again  to  carry  them  away. 

But  our  rain-drop  undergoes  other  changes  more 
strange  than  these.  Till  now  we  have  been  imagining 
it  to  travel  only  where  the  temperature  is  moderate 
enough  for  it  to  remain  in  a  liquid  state  as  water. 
But  suppose  that  when  it  is  drawn  up  into  the  air  it 
meets  with  such  a  cold  blast  as  to  bring  it  to  the 
freezing  point.  If  it  falls  into  this  blast  when  it  is 
already  a  drop,  then  it  will  freeze  into  a  hailstone, 
and  often  on  a  hot  summer's  day  we  may  have  a 
severe  hailstorm,  because  the  rain-drops  have  crossed 
a  bitterly  cold  wind  as  they  were  falling,  and  have 
been  frozen  into  round  drops  of  ice. 

But  if  the  water-vapour  reaches  the  freezing  air 
while  it  is  still  an  invisible  gas,  and  before  it  has 


6b 


THE  I  AIRY-LAND  OF  SCIENCE. 


been  drawn  into  a  drop,  then  its  history  is  very 
different.  The  ordinary  force  of  cohesion  has  then 
no  power  over  the  particles  to  make  them  into  watery 
globes,  but  its  place  is  taken  by  the  fairy  process  of 
crystallization,"  and  they  are  formed  into  beautiful 

white  flakes,  to  fall  in 
a  snow  -  shower.  I 
want  you  to  picture 
this  process  to  your- 
selves, for  if  once  you 
can  take  an  interest  in 
the  wonderful  power 
of  nature  to  build  up 
crystals,  you  will  be 
astonished  how  often, 
you  will  meet  with 
instances  of  it,  and 
what  pleasure  it  will 
add  to  your  life. 

The  particles  of 
nearly  all  substances, 
when  left  free  and 
not  hurried,  can  build 
themselves  into  crystal 
forms.  If  you  melt  salt 
in  water  and  then  let 
all  the  water  evaporate 
slowly,  you  will  get  salt-crystals; — beautiful  cubes  of 
transparent  salt  all  built  on  the  same  pattern.  The 
same  is  true  of  sugar  ;  and  if  you  will  look  at  the 
spikes  of  an  ordinary  stick  of  sugar-candy,  such  as  I 
have  here,  you  will  see  the  kind  of  crystals  which 


/V  piece  of  sugar-candy,  photographed 
of  the  natural  size. 


A  DROP  OF  WATER. 


87 


sugar  forms.  You  may  even  pick  out  such  shapes  as 
these  from  the  common  crystallized  brown  sugar  in 
the  sugar  basin,  or  see  them  with  a  magnifying  glass 
on  a  lump  of  white  sugar. 

But  it  is  not  only  easily  melted  substances  such  as 
sugar  and  salt  which  form  crystals.  The  beautiful 
stalactite  grottos  are  all  made  of  crystals  of  lime. 
Diamonds  are  crystals  of  carbon,  made  inside  the 
earth.  Rock-crystals,  which  you  know  probably  under 
the  name  of  Irish  diamonds,  are  crystallized  quartz  ; 
and  so,  with  slightly  different  colourings,  are  agates, 
opals,  jasper,  onyx,  cairngorms,  and  many  other 
precious  stones.  Iron,  copper,  gold,  and  sulphur, 
when  melted  and  cooled  slowly  build  themselves  into 
crystals,  each  of  their  own  peculiar  form,  and  we  see 
that  there  is  here  a  wonderful  order,  such  as  we  should 
never  have  dreamt  of,  if  v/e  had  not  proved  it.  If 
you  possess  a  microscope  you  may  watch  the  growth 
of  crystals  yourself  by  melting  some  common  pow- 
dered nitre  in  a  little  water  till  you  find  that  no  more 
will  melt  in  it.  Then  put  a  few  drops  of  this  water 
on  a  warm  glass  slide  and  place  it  under  the  micro- 
scope. As  the  drops  dry  you  will  see  the  long 
transparent  needles  of  nitre  forming  on  the  glass,  and 
notice  how  regularly  these  crystals  grow,  not  by 
taking  food  inside  like  living  beings,  but  by  adding 
particle  to  particle  on  the  outside  evenly  and 
regularly. 

Can  we  form  any  idea  why  the  crystals  build  them- 
selves up  so  systematically  1  Dr.  Tyndall  says  we 
can,  and  I  hope  by  the  help  of  these  small  bar 
magnets  to  show  you  how  he  explains  it.  These 


88 


THE  FAIRY-LAND  OF  SCIENCE. 


little  pieces  of  steel,  which  I  hope  you  can  see  lying 
on  this  white  cardboard,  have  been  rubbed  along  a 
magnet  until  they  have  become  magnets  themselves, 
and  I  can  attract  and  lift  up  a  needle  with  any  one  of 
them.  But  if  I  try  to  lift  one  bar  with  another,  I  can 
only  do  it  by  bringing  certain  ends  together.  I  have 
tied  a  piece  of  red  cotton  {Cy  Fig.  21)  round  one  end 
of  each  of  the  magnets,  and  if  I  bring  two  red  ends 
together  they  will  not  cling  together  but  roll  apart. 


Fig.  21. 

A  B 


Bar  magnets  attracting  and  repelling  each  other. 
Cy  Cotton  tied  round  positive  end  of  the  magnet. 


If,  on  the  contrary,  I  put  a  red  end  against  an 
end  where  there  is  no  cotton,  then  the  two  bars  cling 
together.  This  is  because  every  magnet  has  two 
poles  or  points  which  are  exactly  opposite  in  character, 
and  to  distinguish  them  one  is  called  the  positive  pole 
and  the  other  the  negative  pole.  Now  when  I  bring 
two  red  ends,  that  is,  two  positive  poles  together, 
they  drive  each  other  away.  See !  the  magnet  I  am 
not  holding  runs  away  from  the  other.  But  if  I  bring 
a  red  end  and  a  black  end,  that  is,  a  positive  and  a 


A  DROP  OF  WATER. 


89 


negative  end  together,  then  they  are  attracted  and 
cling.  I  will  make  a  triangle  (A,  Fig.  21)  in  which  a 
black  end  and  a  red  end  always  come  together,  and 
you  see  the  triangle  holds  together.  But  now  if  I 
take  off  the  lower  bar  and  turn  it  (B,  Fig.  21)  so  that 
two  red  ends  and  two  black  ends  come  together,  then 
this  bar  actually  rolls  back  from  the  others  down  the 
cardboard.  If  I  were  to  break  these  bars  into  a 
thousand  pieces,  each  piece  would  still  have  two 
poles,  and  if  they  were  scattered  about  near  each 
other  in  such  a  way  that  they  were  quite  free  to 
move,  they  would  arrange  themselves  always  so  that 
two  different  poles  came  together. 

Now  picture  to  yourselves  that  all  the  particles  of 
those  substances  which  form  crystals  have  poles  like 
our  magnets,  then  you  can  imagine  that  when  the 
heat  which  held  them  apart  is  withdrawn  and  the 
particles  come  very  near  together,  they  will  arrange 
themselves  according  to  the  attraction  of  their  poles 
and  so  build  up  regular  and  beautiful  patterns. 

So,  if  we  could  travel  up  to  the  clouds  where  this 
fairy  power  of  crystallization  is  at  work,  we  should 
find  the  particles  of  water-vapour  in  a  freezing 
atmosphere  being  built  up  into  minute  solid  crystals 
of  snow.  If  you  go  out  after  a  snow-shower  and 
search  carefully,  you  will  see  that  the  snow-flakes  are 
not  mere  lumps  of  frozen  water,  but  beautiful  six- 
pointed  crystal  stars,  so  white  and  pure  that  when  we 
want  to  speak  of  anything  being  spotlessly  white,  you 
say  that  it  is  white  as  snow."  Some  of  these  crystals 
are  simply  flat  slabs  with  six  sides,  others  are  stars 
with  six  rods  or  spikes  springing  from  the  centre, 
7 


90 


THE  FAIRY-LAND  OF  SCIENCE. 


others  with  six  spikes  each  formed  like  a  delicate 
fern.  No  less  than  a  thousand  different  forms  of 
delicate   crystals   have  been    found   among  snow- 


Fig.  22. 


Snow- crystals. 


flakes,  but  though  there  is  such  a  great  variety,  yet 
they  are  all  built  on  the  six-sided  and  six-pointed 
plan,  and  are  all  rendered  dazzlingly  white  by  the 
reflection  of  the  light  from  the  faces  of  the  crystals  and 
the  tiny  air-bubbles  built  up  within  them.  This,  you 
see,  is  why,  when  the  snow  melts,  you  have  only  a  little 
dirty  water  in  your  hand  ;  the  crystals  are  gone  and 
there  are  no  more  air-bubbles  held  prisoners  to  act  as 
looking-glasses  to  the  light.  Hoar-frost  is  also  made 
up  of  tiny  water-crystals,  and  is  nothing  more  than 
frozen  dew  hanging  on  the  blades  of  grass  and  from 
the  trees. 

But  how  about  ice  }  Here,  you  will  say,  is  frozen 
water,  and  yet  we  see  no  crystals,  only  a  clear  trans- 
parent mass.  Here,  again,  Dr.  Tyndall  helps  us.  He 
says  (and  as  I  have  proved  it  true,  so  may  you  for 
yourselves,  if  you  will)  that  if  you  take  a  magnifying 
glass,  and  look  down  on  the  surface  of  ice  on  a  sunny 
day,  you  will  see  a  number  of  dark,  six-sided  stars, 
looking  like  flattened  flowers,  and  in  the  centre  of  each 
a  bright  spot.  These  flowers,  which  are  seen  when 
the  ice  is  melting,  are  our  old  friends  the  crystal  stars 


A  DROP  OF  WATER. 


91 


turning  into  water,  and  the  bright  spot  in  the  middle 
is  a  bubble  of  empty  space,  left  because  the  watery 
flower  does  not  fill  up  as  much  room  as  the  ice  of  the 
crystal  star  did. 

Fig  23. 


Water  flowers  in  melting  ice. — Tyndall. 


And  this  leads  us  to  notice  that  ice  always  takes 
up  more  room  than  water,  and  that  this  is  the  reason 
why  our  water-pipes  burst  in  severe  frosts ;  for  as  the 
water  freezes  it  expands  with  great  force,  and  the  pipe 
is  cracked,  and  then  when  the  thaw  comes  on,  and 
the  water  melts  again,  it  pours  through  the  crack  it 
has  made. 

It  is  not  difficult  to  understand  why  ice  should  take 
more  room  ;  for  we  know  that  if  we  were  to  try  to 
arrange  bricks  end  to  end  in  star-like  shapes,  we  must 
leave  some  spaces  between,  and  could  not  pack  them 
so  closely  as  if  they  lay  side  by  side.  And  so, 
when  this  giant  force  of  crystallization  constrains 
the  atoms  of  frozen  water  to  grow  into  star-like 
forms,  the  solid   mass  must   fill  more  room  than 


92 


THE  FAIRY-LAND  OF  SCIENCE, 


the  liquid  water,  and  when  the  star  melts,  this 
space  reveals  itself  to  us  in  the  bright  spot  of  the 
centre. 

We  have  now  seen  our  drop  of  water  under  all  its 
various  forms  of  invisible  gas,  visible  steam,  clou  i 
dew,  hoar-frost,  snow,  and  ice,  and  we  have  only  time 
shortly  to  see  it  on  its  travels,  not  merely  up  and 
down,  as  hitherto,  but  round  the  world. 

We  must  first  go  to  the  sea  as  the  distillery^  or  the 
place  from  which  water  is  drawn  up  invisibly,  in  its 
purest  state,  into  the  air  ;  and  we  must  go  chiefly  to 
the  seas  of  the  tropics,  because  here  the  sun  shines  most 
directly  all  the  year  round,  sending  heat-waves  to  shake 
the  water-particles  asunder.  It  has  been  found  by 
experiment  that,  in  order  to  turn  l  lb.  of  water  into 
vapour,  as  much  heat  must  be  used  as  is  required  to 
melt  5  lbs.  of  iron  ;  and  if  you  consider  for  a  moment 
how  difficult  iron  is  to  melt,  and  how  we  can  keep  an 
iron  poker  in  a  hot  fire  and  yet  it  remains  solid,  this 
will  help  you  to  realize  how  much  heat  the  sun  must 
pour  down  in  order  to  carry  off  such  a  constant  supply 
of  vapour  from  the  tropical  seas. 

Now,  when  all  this  vapour  is  drawn  up  into  the 
air,  we  know  that  some  of  it  will  form  into  clouds 
as  it  gets  chilled  high  up  in  the  sky,  and  then  it  will 
pour  down  again  in  those  tremendous  floods  of  rain 
which  occur  in  the  tropics. 

But  the  sun  and  air  will  not  let  it  all  fall  down  at 
once,  and  the  winds  which  are  blowing  from  the 
equator  to  the  poles  cairy  large  masses  of  it  away 
with  them.    Then,  as  you  know,  it  will  depend  on 


A  DROP  OF  WATER, 


93 


many  things  how  far  this  vapour  is  carried.  Some  of 
it,  chilled  by  cold  blasts,  or  by  striking  on  cold  moun- 
tain tops,  as  it  travels  northwards,  will  fall  in  rain 
in  Europe  and  Asia,  while  that  which  travels  south- 
wards may  fall  in  South  America,  Australia,  or  New 
Zealand,  or  be  carried  over  the  sea  to  the  South  Pole. 
Wherever  it  falls  on  the  land  as  rain,  and  is  not  used 
by  plants,  it  will  do  one  of  two  things ;  either  it  will 
run  down  in  streams  and  form  brooks  and  rivers,  and 
so  at  last  find  its  way  back  to  the  sea,  or  it  will  sink 
deep  in  the  earth  till  it  comes  upon  some  hard  r  ck 
through  which  it  cannot  get,  and  then,  being  hard 
pressed  by  the  water  coming  on  behind,  it  will  rise  up 
again  through  cracks,  and  come  to  the  surface  as  a 
spring.  These  springs,  again,  feed  rivers,  sometimes 
above-ground,  sometimes  for  long  distances  under- 
ground ;  but  one  way  or  another  at  last  the  whole 
drains  back  into  the  sea. 

But  if  the  vapour  travels  on  till  it  reaches  high  moun- 
tains in  cooler  lands,  such  as  the  Alps  of  Switzerland ; 
or  is  carried  to  the  poles  and  to  such  countries  as  Green- 
land or  the  Antarctic  Continent,  then  it  will  come 
down  as  snow,  forming  immense  snow-fields.  And 
here  a  curious  change  takes  place  in  it.  If  you  make 
an  ordinary  snowball  and  work  it  firmly  together,  it 
becomes  very  hard,  and  if  you  then  press  it  forcibly  into 
a  mould  you  can  turn  it  into  transparent  ice.  And 
in  the  same  way  the  snow  which  falls  in  Greenland 
and  on  the  high  mountains  of  Switzerland  becomes 
very  firmly  pressed  together,  as  it  slides  down  into 
the  valleys.  It  is  like  a  crowd  of  people  passing 
from  a  broad  thoroughfare  into  a  narrow  street.  As 


94 


THE  FAIRY-LAND  OF  SCIENCE. 


the  valley  grows  narrower  and  narrower  the  great 
mass  of  snow  in  front  cannot  move  down  quickly, 
while  more  and  more  is  piled  up  by  the  snowfall 
behind,  and  the  crowd  and  crush  grow  denser  and 
denser.  In  this  way  the  snow  is  pressed  together  till 
the  air  that  was  hidden  in  its  crystals,  and  which  gave 
it  its  beautiful  whiteness,  is  all  pressed  out,  and  the 
snow-crystals  themselves  are  squeezed  into  one  solid 
mass  of  pure,  transparent  ice. 

Then  we  have  what  is  called  a  "  glacier,"  or  river  of 
ice,  and  this  solid  river  comes  creeping  down  till,  in 
Greenland,  it  reaches  the  edge  of  the  sea.  There  it 
is  pushed  over  the  brink  of  the  land,  and  large  pieces 
snap  off,  and  we  have  "icebergs."  These  icebergs  — 
made,  remember,  of  the  same  water  which  was  first 
drawn  up  from  the  tropics — float  on  the  wide  sea,  and 
melting  in  its  warm  currents,  topple  over  and  over* 
till  they  disappear  and  mix  with  the  water,  to  be 
carried  back  again  to  the  warm  ocean  from  which 
they  first  started.  In  Switzerland  the  glaciers  cannot 
reach  the  sea,  but  they  move  down  into  the  valleys 
till  they  come  to  a  warmer  region,  and  there  the  end 
of  the  glacier  melts,  and  flows  away  in  a  stream.  The 
Rhone  and  many  other  rivers  are  fed  by  the  glaciers 
of  the  Alps  ;  and  as  these  rivers  flow  into  the  sea,  our 
drop  of  water  again  finds  its  way  back  to  its  home. 

But  when  it  joins  itself  in  this  way  to  its  com- 
panions, from  whom  it  was  parted  for  a  time,  does 

*  A  floating  iceberg  must  have  about  eight  times  as  much  ice  under 
the  water  as  it  has  above,  and  therefore,  when  the  lower  part  melts 
in  a  warm  current,  the  iceberg  loses  its  balance  and  tilts  over,  so  as  to 
rearrange  itself  round  the  centre  of  gravity. 


A  DROP  OF  WATER. 


95 


it  come  back  clear  and  transparent  as  it  left  them  ? 
From  the  iceberg  it  does  indeed  return  pure  and 
clear ;  for  the  fairy  Crystallization  will  have  no 
impurities,  not  even  salt,  in  her  ice-crystals,  and  so  as 
they  melt  they  give  back  nothing  but  pure  water  to 
the  sea.  Yet  even  icebergs  bring  down  earth  and 
stones  frozen  into  the  bottom  of  the  ice,  and  so  they 
feed  the  sea  with  mud. 

But  the  drops  of  water  in  rivers  are  by  no  means 
as  pure  as  when  they  rose  up  into  the  sky.  We 
shall  see  in  the  next  lecture  how  rivers  carry  down 
not  only  sand  and  mud  all  along  their  course,  but 
even  solid  matter  such  as  salt,  lime,  iron,  and  flint, 
dissolved  in  the  clear  water,  just  as  sugar  is  dissolved, 
vvithout  our  being  able  to  see  it.  The  water,  too, 
which  has  sunk  down  into  the  earth,  takes  up  much 
matter  as  it  travels  along.  You  all  know  that  the 
water  you  drink  from  a  spring  is  very  different  from 
rain-water,  and  you  will  often  find  a  hard  crust  at 
the  bottom  of  kettles  and  in  boilers,  which  is  formed 
of  the  carbonate  of  lime  which  is  driven  out  of 
the  clear  water  when  it  is.  boiled.  The  water  has 
become  "  hard "  in  consequence  of  having  picked 
up  and  dissolved  the  carbonate  of  lime  on  its  way 
through  the  earth,  just  in  the  same  way  as  water  would 
become  sweet  if  you  poured  it  through  a  sugar-cask. 
You  will  also  have  heard  of  iron-springs,  sulphur- 
springs,  and  salt-springSj  which  come  out  of  the  earth, 
even  if  you  have  never  tasted  any  of  them,  and  the 
water  of  all  these  springs  finds  its  way  back  at  last 
to  the  sea.  - 

And  now,  can   you  understand   why  sea-water 


96  THE  FAIRY-LAND  OF  SCIENCE. 


should  taste  salt  and  bitter?  Every  drop  of  water 
which  flovv's  from  the  earth  to  the  sea  carries  some- 
thing with  it.  Generally,  there  is  so  little  of  any  sub- 
stance in  the  water  that  we  cannot  taste  it,  and  we 
call  it  pure  water  ;  but  the  purest  of  spring  or  river- 
water  has  always  some  solid  matter  dissolved  in  it, 
and  all  this  goes  to  the  sea.  Now,  when  the  sun- 
waves  come  to  take  the  water  out  of  the  sea  again, 
they  will  have  nothing  but  the  pure  water  itself;  and 
so  all  these  salts  and  carbonates  and  other  solid 
substances  are  left  behind,  and  we  taste  them  in  sea- 
water. 

Some  day,  when  you  are  at  the  seaside,  take 
some  sea-water  and  set  it  on  the  hob  till  a  great 
deal  has  simmered  gently  away,  and  the  liquid 
is  very  thick.  Then  take  a  drop  of  this  liquid,  and 
examine  it  under  a  microscope.  As  it  dries  up 
gradually,  you  will  see  a  number  of  crystals  forming, 
some  square — and  these  will  be  crystals  of  ordinary 
salt ;  some  oblong — these  will  be  crystals  of  gypsum 
or  alabaster ;  and  others  of  various  shapes.  Then, 
when  you  see  how  much  matter  from  the  land  is 
contained  in  sea-water,  you  will  no  longer  wonder 
that  the  sea  is  salt  ;  on  the  contrary,  you  will  ask, 
Why  does  it  not  grow  Salter  every  year  } 

The  answer  to  this  scarcely  belongs  to  our  history 
of  a  drop  of  water,  but  I  must  just  suggest  it  to  you. 
In  the  sea  are  numbers  of  soft-bodied  animals,  like 
the  jelly  animals  which  form  the  coral,  which  require 
hard  material  for  their  shells  or  the  solid  branches  on 
which  they  live,  and  they  are  greedily  watching  for 
these  atoms  of  lime,  of  flint,  of  magnesia,  and  of  other 


A  DROP  OF  WA  TER. 


97 


substances  brought  down  into  the  sea.  It  is  with 
lime  and  magnesia  that  the  tiny  chalk-builders  form 
their  beautiful  shells,  and  the  coral  animals  theii 
skeletons,  while  another  class  of  builders  use  the  flint ; 
and  when  these  creatures  die,  their  remains  go  to 
form  fresh  land  at  the  bottom  of  the  sea ;  and  so, 
though  the  earth  is  being  washed  away  by  the 
rivers  and  springs  it  is  being  built  up  again,  out 
of  the  same  materials,  in  the  depths  of  the  great 
ocean. 

And  now  we  have  reached  the  end  of  the  travels  of 
our  drop  of  water.  We  have  seen  it  drawn  up  by  the 
fairy  "  heat,"  invisible  into  the  sky  ;  there  fairy  "  co- 
hesion  "  seized  it,  and  formed  it  into  water-drops,  and 
the  giant,  "gravitation,"  pulled  it  down  again  to  the 
earth.  Or,  if  it  rose  to  freezing  regions,  the  fairy  of 
"  crystallization  "  built  it  up  into  snow-crystals,  again 
to  fall  to  the  earth,  and  either  to  be  melted  back  into 
water  by  heat,  or  to  slide  down  the  valleys  by  force 
of  gravitation,  till  it  became  squeezed  into  ice.  We 
have  detected  it,  when  invisible,  forming  a  veil  round 
our  earth,  and  keeping  off  the  intense  heat  of  the  sun's 
rays  by  day,  or  shutting  it  in  by  night.  We  have  seen 
it  chilled  by  the  blades  of  grass,  forming  sparkling 
dew-drops  or  crystals  of  hoar-frost,  glistening  in 
the  early  morning  sun  ;  and  we  have  seen  it  in  the 
dark  underground,  being  drunk  up  greedily  by  the 
roots  of  plants.  We  have  stajted  with  it  from  the 
tropics,  and  travelled  over  land  and  sea,  watch- 
ing it  forming  rivers,  or  flowing  underground  in 
springs,  or  moving  onwards  to  the  high  mountains 
or  the  poles,  and  coming  back  again  in  glaciers  and 


9»  THE  FAIRY-LAND  OF  SCIENCE. 


icebergs.  Through  all  this,  while  it  is  being  carried 
hither  and  thither  by  invisible  power,  we  find  no  trace 
of  its  becoming  worn  out,  or  likely  to  rest  from  its 
labours.  Ever  onwards  it  goes,  up  and  down,  and 
round  and  round  the  world,  taking  many  forms,  and 
performing  many  wonderful  feats.  We  have  seen 
some  of  the  work  that  it  does,  in  refreshing  the  air, 
feeding  the  plants,  giving  us  clear,  sparkling  water  to 
drink,  and  carrying  matter  to  the  sea  ;  but  besides 
this,  it  does  a  wonderful  work  in  altering  all  the  face 
of  our  earth.  This  work  we  shall  consider  in  the 
next  lecture,  on  The  two  great  Sculptors— Water 
2,pd  Ice." 


THE  TWO  GREAT  SCULPTORS,  OQ 


LECTURE  V. 

THE  TWO  GREAT  SCULPTORS— WATER  AND  ICE. 


[I^^^^^^^H^^^^^j  N  our  last  lecture  we  saw 
h  '^^  that  water  can  exist  in 

three  forms  : — ist,  as  an 
invisible  vapour ;  2nd,  as  liquid  water ;  3rd,  as  solid 
snow  and  ice. 

To-day  we  are  going  to  take  the  two  last 


lOO  THE  FAIRY-LAND  OF  SCIENCE. 


these  forms,  water  and  ice,  and  speak  of  them  as 
sculptors. 

To  understand  why  they  deserve  this  name  we  must 
first  consider  what  the  work  of  a  sculptor  is.  If  you 
go  into  a  statuary  yard  you  will  find  there  large 
blocks  of  granite,  marble,  and  other  kinds  of  stone, 
hewn  roughly  into  different  shapes ;  but  if  you  pass 
into  the  studio,  where  the  sculptor  himself  is  at  work, 
you  will  find  beautiful  statues,  more  or  less  finished  ; 
and  you  will  see  that  out  of  rough  blocks  of  stone  he 
has  been  able  to  cut  images  which  look  like  living 
forms.  You  can  even  see  by  their  faces  whether  they 
are  intended  to  be  sad,  or  thoughtful,  or  gay,  and  by 
their  attitude  whether  they  are  writhing  in  pain,  or 
dancing  with  joy,  or  resting  peacefully.  How  has  all 
this  history  been  worked  out  from  the  shapeless 
stone  }  It  has  been  done  by  the  sculptor's  chisel.  A 
piece  chipped  off  here,  a  wrinkle  cut  there,  a  smooth 
surface  rounded  off  in  another  place,  so  as  to  give  a 
gentle  curve ;  all  these  touches  gradually  shape  the 
figure  and  mould  it  out  of  the  rough  stone,  first  into 
a  rude  shape  and  afterwards,  by  delicate  strokes,  into 
the  form  of  a  living  being. 

Now,  just  in  the  same  way  as  the  wrinkles  and  curves 
of  a  statue  are  cut  by  the  sculptors  chisel,  so  the  hills 
and  valleys,  the  steep  slopes  and  gentle  curves  on  the 
face  of  our  earth,  giving  it  all  its  beauty,  and  the 
varied  landscapes  we  love  so  well,  have  been  cut  out 
by  water  and  ice  passing  over  them.  It  is  true  that 
some  of  the  greater  wrinkles  of  the  earth,  the  lofty 
mountains,  and  the  high  masses  of  land  which  rise 
above  the  sea,  have  been  caused  by  earthquakes  and 


THE  TWO  GREAT  SCULPTORS,  lOI 


shrinking  of  the  earth.  We  shall  not  speak  of  these 
to-day,  but  put  them  aside  as  belonging  to  the  rough 
work  of  the  statuary  yard.  But  when  once  these  large 
masses  are  put  ready  for  water  to  work  upon,  then  ali 
the  rest  of  the  rugged  wrinkles  and  gentle  slopes  which 
make  the  country  so  beautiful  are  due  to  water  and 
ice  ;  and  for  this  reason  I  have  called  them  ''sculptors." 

Go  for  a  walk  In  the  country,  or  notice  the  land- 
scape as  you  travel  on  a  railway  journey.  You  pass 
by  hills  and  through  valleys,  through  narrow  steep 
gorges  cut  in  hard  rock,  or  through  wild  ravines  up 
the  sides  of  which  you  can  hardly  scramble.  Then 
you  come  to  grassy  slopes  and  to  smooth  plains 
across  which  you  can  look  for  miles  without  seeing  a 
hill  ;  or,  when  you  arrive  at  the  seashore,  you  clamber 
into  caves  and  grottos,  and  along  dark  narrow  pas- 
sages leading  from  one  bay  to  another.  All  these  — 
hills,  valleys,  gorges,  ravines,  slopes,  plains,  caves, 
grottos,  and  rocky  shores  —  have  been  cut  out  by 
water.  Day  by  day  and  year  by  year,  while  every- 
thing seems  to  us  to  remain  the  same,  this  industrious 
sculptor  is  chipping  away,  a  few  grains  here,  a  corner 
there,  a  large  mass  in  another  place,  till  he  gives  to 
the  country  its  own  peculiar  scenery,  just  as  the 
human  sculptor  gives  expression  to  his  statue. 

Our  work  to-day  will  consist  in  trying  to  form  some 
idea  of  the  way  in  which  water  thus  carves  out  the 
surface  of  the  earth,  and  we  will  begin  by  seeing  how 
much  can  be  done  by  our  old  friends  the  rain- drops 
before  they  become  running  streams. 

Everyone  must  have  noticed  that  whenever  rain 
falls  on  soft  ground  it  makes  small  round  holes  in 


I02  THE  FAIRY-LAND  OF  SCIENCE, 


which  it  collects,  and  then  sinks  into  the  ground, 
forcing  its  way  between  the  grains  of  earth.  But  you 
would  hardly  think  that  the  beautiful  pillars  in  Fig.  24 
have  been  made  entirely  in  this  way  by  rain  beating 
upon  and  soaking  into  the  ground. 

Fig.  24. 


Earth- pillars  near  Botzen,  in  the  Tycol. 
(Adapted  from  Lyell's  *  Principles.') 


Where  these  pillars  stand  there  was  once  a  solid 
mass  of  clay  and  stones,  into  which  the  rain-drops 
crept,  loosening  the  earthy  particles ;  and  then  when 
the  sun  dried  the  earth  again  cracks  were  formed,  so 
that  the  next  shower  loosened  it  still  more,  and  carried 
some  of  the  mud  down  into  the  valley  below.  But 
here  and  there  large  stones  were  buried  in  the  clay, 
and  where  this  happened  the  rain  could  not  penetrate, 


THE  TWO  GREAT  SCULPTORS.  IO3 


and  the  stones  became  the  tops  of  tall  pillais  of  clay, 
washed  into  shape  by  the  rain  beating  on  its  sides,  but 
escaping  the  general  destruction  of  the  rest  of  the 
mud.  In  this  way  the  whole  valley  has  been  carved 
out  into  fine  pillars,  some  still  having  capping-stones, 
while  others  have  lost  them,  and  these  last  will  soon 
be  washed  away.  We  have  no  such  valleys  of  earth- 
pillars  here  in  England,  but  you  may  sometimes  see 
tiny  pillars  under  bridges  where  the  drippings  have 
washed  away  the  earth  between  the  pebbles,  and  such 
small  examples  which  you  can  observe  for  yourselves 
are  quite  as  instructive  as  more  important  ones. 

Another  way  in  which  rain  changes  the  surface  of  the 
earth  is  by  sinking  down  through  loose  soil  from  the  top 
of  a  cliff  to  a  depth  of  many  feet  till  it  comes  to  solid 
rock,  and  then  lying  spread  over  a  wide  apace.  Here 
it  makes  a  kind  of  watery  mud,  which  is  a  very  unsafe 
foundation  for  the  hill  of  earth  above  it,  and  so  after 
a  time  the  whole  mass  slips  down  and  makes  a  fresh 
piece  of  land  at  the  foot  of  the  cliff.  If  you  have  ever 
been  at  the  Isle  of  Wight  you  will  have  seen  an 
undulating  strip  of  ground,  called  the  Undercliff,  at 
Ventnor  and  other  places,  stretching  all  along  the  sea 
below  the  high  cliffs.  This  land  was  once  at  the  top 
of  the  cliff,  and  came  down  by  a  succession  of  landslips 
such  as  we  have  been  describing.  A  very  great  land- 
slip of  this  kind  happened  in  the  memory  of  living 
people,  at  Lyme  Regis,  in  Dorsetshire,  in  the  year 

1839. 

You  will  easily  see  how  in  forming  earth-pillars  and 
causing  landslips  rain  changes  the  face  of  the  country, 


I04  THE  FAIRY-LAND  OF  SCIENCE. 

but  these  are  only  rare  effects  of  water.  It  is  when  the 
rain  collects  in  brooks  and  forms  rivers  that  it  is  most 
busy  in  sculpturing  the  land.  Look  out  some  day 
into  the  road  or  the  garden  where  the  ground  slopes  a 
little,  and  watch  what  happens  during  a  shower  of 
rain.  First  the  rain-drops  run  together  in  every  little 
hollow  of  the  ground,  then  the  water  begins  to  flow 
along  any  ruts  or  channels  it  can  find,  lying  here  and 
there  in  pools,  but  always  making  its  way  gradually 
*  down  the  slope.  Meanwhile  from  other  parts  of  the 
ground  little  rills  are  coming,  and  these  all  meet  in 
some  larger  ruts  where  the  ground  is  lowest,  making 
one  great  stream,  which  at  last  empties  itself  into  the 
gutter  or  an  area,  or  finds  its  way  down  some  grating. 

Now  just  this,  which  we  can  watch  whenever  a 
heavy  shower  of  rain  comes  down  on  the  road,  happens 
also  all  over  the  world.  Up  in  the  mountains,  where 
there  is  always  a  great  deal  of  rain,  little  rills  gather 
and  fall  over  the  mountain  sides,  meeting  in  some 
stream  below.  Then,  as  this  stream  flows  on,  it  is  fed 
by  many  runnels  of  water,  which  come  from  all  parts 
of  the  country,  trickling  along  ruts,  and  flowing  in 
small  brooks  and  rivulets  down  the  gentle  slope  of  the 
land  till  they  reach  the  big  stream,  which  at  last  is 
important  enough  to  be  called  a  river.  Sometimes 
this  river  comes  to  a  large  hollow  in  the  land  and 
there  the  water  gathers  and  forms  a  lake ;  but  still  at 
the  lower  end  of  this  lake  out  it  comes  again,  forming 
a  new  river,  and  growing  and  growing  by  receiving 
fresh  streams  until  at  last  it  reaches  the  sea. 

The  River  Thames,  which  you  all  know,  and  whose 
course  you  will  find  clearly  described  in  Mr.  Huxley's 


THE  TWO  GREAT  SCULPTORS,  lOS 


*  Physiography/  drains  in  this  way  no  less  than  one- 
seventh  of  the  whole  of  England.  All  the  rain  which 
falls  in  Berkshire,  Oxfordshire,  Middlesex,  Hertford- 
shire, Surrey,  the  north  of  Wiltshire  and  north-west 
of  Kent,  the  south  of  Buckinghamshire  and  of  Glou- 
cestershire, finds  its  way  into  the  Thames;  making 
an  area  of  6160  square  miles  over  which  every  little 
rivulet  and  brook  trickle  down  to  the  one  great  river, 
which  bears  them  to  the  ocean.  And  so  with  every 
other  area  of  land  in  the  world  there  is  some  one 
channel  towards  which  the  ground  on  all  sides  slopes 
gently  down,  and  into  this  channel  all  the  water  will 
run,  on  its  way  to  the  sea. 

But  what  has  this  to  do  with  sculpture  or  cutting 
out  of  valleys  }  If  you  will  only  take  a  glass  of  water 
out  of  any  river,  and  let  it  stand  for  some  hours,  you 
will  soon  answer  this  question  for  yourself.  For  you 
will  find  that  even  from  river  water  which  looks  quite 
clear,  a  thin  layer  of  mud  will  fall  to  the  bottom  of 
the  glass,  and  if  you  take  the  water  when  the  river  is 
swollen  and  muddy  you  w^ill  get  quite  a  thick  deposit. 
This  shows  that  the  brooks,  the  streams,  and  the  rivers 
wash  away  the  land  as  they  flow  over  it  and  carry  it 
from  the  mountains  down  to  the  valleys,  and  from  the 
valleys  away  out  into  the  sea. 

But  besides  earthy  matter,  which  we  can  see,  there 
is  much  matter  dissolved  in  the  water  of  rivers  (as  we 
mentioned  in  the  last  lecture),  and  this  we  cannot  see. 

If  you  use  water  which  comes  out  of  a  chalk 
country  you  w^ill  find  that  after  a  time  the  kettle  in 
which  you  have  been  in  the  habit  of  boiling  this  water 
has  a  hard  crust  on  its  bottom  and  sides,  and  this  crust 
8 


I06  THE  FAIRY-LAND  OF  SCIENCE. 

IS  made  of  chalk  or  carbonate  of  lime,  which  the  watef 
took  out  of  the  rocks  when  it  was  passing  through 
them.  Professor  Bischofif  has  calculated  that  the  river 
Rhine  carries  past  Bonn  every  year  enough  carbonate 
of  lime  dissolved  in  its  water  to  make  332,000  million 
oyster-shells,  and  that  if  all  these  shells  were  built  into 
a  cube  it  would  measure  560  feet. 

Imagine  to  yourselves  the  whole  of  St.  Pauls 
churchyard  filled  with  oyster-shells,  built  up  in  a  large 
square  till  they  reached  half  as  high  again  as  the  top 
of  the  cathedral,  then  you  will  have  some  idea  of  the 
amount  of  chalk  carried  invisibly  past  Bonn  in  the 
water  of  the  Rhine  every  year. 

Since  all  this  matter,  whether  brought  down  as 
mud  or  dissolved,  comes  from  one  part  of  the  land 
to  be  carried  elsewhere  or  out  to  sea,  it  is  clear  that 
some  gaps  and  hollows  must  be  left  in  the  places  from 
which  it  is  taken.  Let  us  see  how  these  gaps  are 
made.  Have  you  ever  clambered  up  the  mountain- 
side, or  even  up  one  of  those  small  ravines  in  the  hill- 
side, which  have  generally  a  little  stream  trickling 
through  them  ?  If  so,  you  must  have  noticed  the 
number  of  pebbles,  large  and  small,  lying  in  patches 
here  and  there  in  the  stream,  and  many  pieces  of 
broken  rock,  which  are  often  scattered  along  the  sides 
of  the  ravine  ;  and  how,  as  you  climb,  the  path  grows 
steeper,  and  the  rocks  become  rugged  and  stick  out 
in  strange  shapes. 

The  history  of  this  ravine  w^ill  tell  us  a  great 
deal  about  the  carving  of  water.  Once  it  was  nothing 
more  than  a  little  furrow  in  the  hill-side  down  which 
the  rain  found  its  way  in  a  thin  thread-like  stream. 
But  by  and  by,  as  the  stream  carried  down  some  of 


THE  TWO  GREAT  SCULPTORS. 


the  earth,  and  the  furrow  grew  deeper  and  wider,  the 
sides  began  to  crumble  when  the  sun  dried  up  the 
rain  which  had  soaked  in.  Then  in  winter,  when  the 
sides  of  the  hill  were  moist  with  the  autumn  rains, 
frost  came  and  turned  the  water  to  ice,  and  so  made 

Fig.  25. 


Ravine  worn  by  water  in  the  side  of  a  hill. 


the  cracks  still  larger,  and  the  swollen  stream  rushing 
down,  caught  the  loose  pieces  of  rock  and  washed 
them  down  into  its  bed.  Here  they  were  rolled  over 
and  over,  and  grated  against  each  other,  and  were 
ground  av.  ay  till  they  became  rounded  pebbles,  such 
as  lie  in  the  foreground  of  the  picture  (Fig.  25)  ;  while 


I08  THE  FAIRY-LAND  OF  SCIENCE. 


the  grit  which  was  rubbed  off  them  was  carried 
farther  down  by  the  stream.  And  so  in  time  this 
became  a  Httle  valley,  and  as  the  stream  cut  it  deeper 
and  deeper,  there  was  room  to  clamber  along  the 
sides  of  it,  and  ferns  and  mosses  began  to  cover 
the  naked  stone,  and  small  trees  rooted  themselves 
along  the  banks,  and  this  beautiful  little  nook  sprang 
up  on  the  hill-side  entirely  by  the  sculpturing  of 
water. 

Shall  you  not  feel  a  fresh  interest  in  all  the  little 
valleys,  ravines,  and  gorges  you  meet  with  in  the 
country,  if  you  can  picture  them  being  formed  in  this 
way  year  by  year  ?  There  are  many  curious  differences 
in  them  which  you  can  study  for  yourselves.  Some 
will  be  smooth,  broad  valleys,  and  here  the  rocks  have 
been  soft  and  easily  worn,  and  water  trickling  down 
the  sides  of  the  first  valley  has  cut  other  channels  so 
as  to  make  smaller  valleys  running  across  it.  In  other 
places  there  will  be  narrow  ravines,  and  here  the  rocks 
have  been  hard,  so  that  they  did  not  wear  away 
gradually,  but  broke  off  and  fell  in  blocks,  leaving 
high  cliffs  on  each  side.  In  some  places  you  will  come 
to  a  beautiful  waterfall,  where  the  water  has  tumbled 
over  a  steep  cliff,  and  then  eaten  its  way  back,  just 
like  a  saw  cutting  through  a  piece  of  wood. 

There  are  two  things  in  particular  to  notice  in  a 
waterfall  like  this.  First,  how  the  water  and  spray 
dash  against  the  bottom  of  the  cliff  down  which  it 
falls,  and  grind  the  small  pebbles  against  the  rock. 
In  this  way  the  bottom  of  the  cliff  is  undermined,  and 
so  great  pieces  tumble  down  from  time  to  time,  and 
keep  the  fall  upright  instead  of  its  being  sloped  away 


THE  TWO  GREAT  SCULPTORS,  109 


at  the  top,  and  becoming  a  mere  stream.  Secondly, 
you  may  often  see  curious  cup-shaped  holes,  called 

pot-holes,"  in  the  rocks  on  the  sides  of  a  waterfall, 
and  these  also  are  concerned  in  its  formation.  In  these 
holes  you  will  generally  find  two  or  three  small 
pebbles,  and  you  have  here  a  beautiful  example  of 
how  water  uses  stones  to  grind  away  the  face  of  the 
earth.  These  holes  are  made  entirely  by  the  falling 
water  eddying  round  and  round  in  a  small  hollow  of 
the  rock,  and  grinding  the  pebbles  which  it  has 
brought  down,  against  the  bottom  and  sides  of  this 
hollow,  just  as  you  grind  round  a  pestle  in  a  mortar. 
By  degrees  the  hole  grows  deeper  and  deeper,  and 
though  the  first  pebbles  are  probably  ground  down 
to  powder,  others  fall  in,  and  so  in  time  there  is  a 
great  hole  perforated  right  through,  helping  to  make 
the  rock  break  and  fall  av/ay. 

In  this  and  other  ways  the  water  works  its  way 
back  in  a  surprising  manner.  The  Isle  of  Wight  gives 
us  some  good  instances  of  this  ;  Alum  Bay  Chine 
and  the  celebrated  Blackgang  Chine  have  been  en- 
tirely cut  out  by  waterfalls.  But  the  best  known  and 
most  remarkable  example  is  the  Niagara  Falls,  in 
America.  Here,  the  River  Niagara  first  wanders 
through  a  fiat  country,  and  then  reaches  the  great 
Lake  Erie  in  a  hollow  of  the  plain.  After  that,  it 
flows  gently  down  for  about  fifteen  miles,  and  then  the 
slope  becomes  greater  and  it  rushes  on  to  the  Falls  of 
Niagara.  These  falls  are  not  nearly  so  high  as  many 
[>eople  imagine,  being  only  165  feet,  or  about  half  the 
height  of  St.  Paul's  Cathedral,  but  they  are  2700  feet 
or  nearly  half-a-mile  wide,  and  no  less  than  670,000 


flO  THE  FAIRY-LAND  OF  SCIENCE. 

tons  of  water  fall  over  them  every  minute,  making 
magnificent  clouds  of  spray. 

Fig.  26. 


Bird's-eye  view  of  Lake  Erie,  Niagara  Falls,  and  Queensiovvn. 

(Lyell.) 

Sir  Charles  Lyell,  when  he  was  at  Niagara,  came 
to  the  conclusion  that,  taking  one  year  with  another, 
these  falls  eat  back  the  cliff  at  the  rate  of  about  one 
foot  a  year,  as  you  can  easily  imagine  they  would  do, 
when  you  think  with  what  force  the  water  must  dasl'i 
against  the  bottom  of  the  falls.  In  this  way  a  deep 
cleft  has  been  cut  right  back  from  Queenstown  for  a 
distance  of  seven  miles,  to  the  place  where  the  falls 
now  are.    This  helps  us  a  little  to  understand  how 


Fig.  27. 


THE  TWO  GREA  T  SCULPTORS.  1 1 1 


very  slowly  and  gradually  water  cuts  its  way  ;  for  if 
a  foot  a  year  is  about  the  average  of  the  waste  of  the 
rock,  it  will  have  taken  more  than  thirty-five  thousand 
years  for  that  channel  of  seven  miles  to  be  made. 

But  even  this  chasm  cut  by  the  falls  of  Niagara  is 
nothing  compared  with  the  canons  of  Colorado.  Canon 
is  a  Spanish  word  for  a  rocky  gorge,  and  these  gorges 
are  indeed  so  grand,  that  if  we  had  not  seen  in  other 
places  what  water  can  do,  we  should  never  have  been 
able  to  believe  that  it  could  have  cut  out  these  gigantic 
chasms.  For  more  than  three  hundred  miles  the  River 
Colorado,  coming  down  from  the  Rocky  Mountains, 
has  eaten  its  way  through  a  country  made  of  granite 
and  hard  beds  of  limestone  and  sandstone,  and  it  has 
cut  down  straight  through  these  rocks,  leaving  walls 
from  half-a-mile  to  a  mile  high,  standing  straight  up 
from  it.  The  cliffs  of  the  Great  Canon,  as  it  is  called, 
stretch  up  for  more  than  a  mile  above  the  river 
which  flows  in  the  gorge  below !  Fancy  yourselves 
for  a  moment  in  a  boat  on  this  river,  as  shown  in 
Figure  27,  and  looking  up  at  these  gigantic  walls  of 
rock  towering  above  you.  Even  half-way  up  them, 
a  man,  if  he  could  get  there,  would  be  so  small  you 
could  not  see  him  without  a  telescope  ;  while  the 
opening  at  the  top  between  the  two  walls  would  seem 
so  narrow  at  such  an  immense  distance  that  the  sky 
above  would  have  the  appearance  of  nothing  more 
than  a  narrow  streak  of  blue.  Yet  these  huge  chasms 
have  not  been  made  by  any  violent  breaking  apart 
of  the  rocks  or  convulsion  of  an  earthquake.  No, 
they  have  been  gradually,  silently,  and  steadily  cut 
through  by  the  river  which  now  glides  quietly  in  the 


112  THE  FAIRY-LAND  OF  SCIENCE. 


wider  chasms,  or  rushes  rapidly  through  the  narro\'y 
gorges  at  their  feet. 

"  No  description/'  says  Lieutenant  Ives,  one  of  the 
first  explorers  of  this  river,  "  can  convey  the  idea  of 
the  varied  and  majestic  grandeur  of  this  peerless  water- 
way. Wherever  the  river  turns,  the  entire  panorama 
changes.  Stately  fagades,  august  cathedrals,  amphi- 
theatres, rotundas,  castellated  walls,  and  rows  of 
time-stained  ruins,  surmounted  by  every  form  of 
tower,  minaret,  dome  and  spire,  have  been  moulded 
from  the  cyclopean  masses  of  rock  that  form  the 
mighty  defile.*'  Who  will  say,  after  this,  that  water  is 
not  the  grandest  of  all  sculptors,  as  it  cuts  through 
hundreds  of  miles  of  rock,  forming  such  magnificent 
granite  groups,  not  only  unsurpassed  but  unequalled 
by  any  of  the  works  of  man  ? 

But  we  must  not  look  upon  water  only  as  a  cutting 
instrument,  for  it  does  more  than  merely  carve  out 
land  in  one  place,  it  also  carries  it  away  and  lays  it 
down  elsewhere  ;  and  in  this  it  is  more  like  a  modeller 
in  clay,  who  smooths  off  the  material  from  one  part  of 
his  figure  to  put  it  upon  another. 

Running  water  is  not  only  always  carrying  away 
mud,  but  at  the  same  time  laying  it  down  here  and 
there  wherever  it  flows.  When  a  torrent  brings  down 
stones  and  gravel  from  the  mountains,  it  will  depend 
on  the  size  and  weight  of  the  pieces  how  long  they 
will  be  in  falling  through  the  water.  If  you  take  a 
handful  of  gravel  and  throw  it  into  a  glass  full  of 
water,  you  v/ill  notice  that  the  stones  in  it  will  fall  to 
.the  bottom  at  once,  the  grit  and  coarse  sand  will  take 


THE  TWO  GREAT  SCULPTORS, 


113 


longer  in  sinking,  and  lastly,  the  fine  sand  will  be  an 
hour  or  two  in  settling  down,  so  that  the  water 
becomes  clear.  Now,  suppose  that  this  gravel  were 
sinking  in  the  water  of  a  river.  The  stones  would  be 
buoyed  up  as  long  as  the  river  was  very  full  and 
flowed  very  quickly,  but  they  would  drop  through 
sooner  than  the  coarse  sand.  The  coarse  sand  in  its 
turn  would  begin  to  sink  as  the  river  flowed  more 
slowly,  and  would  reach  the  bottom  while  the  fine 
sand  was  still  borne  on.  Lastly,  the  fine  sand  would 
sink  through  very,  very  slowly,  and  only  settle  in 
comparatively  still  water. 

From  this  it  will  happen  that  stones  will  generally 
lie  near  to  the  bottom  of  torrents  at  the  foot  of  the 
banks  from  which  they  fall,  while  the  gravel  will  be 
carried  on  by  the  stream  after  it  leaves  the  mountains. 
This  too,  however,  will  be  laid  down  when  the  river 
comes  into  a  more  level  country  and  runs  more  slowly. 
Or  it  maybe  left  together  with  the  finer  mud  in  a  lake, 
as  in  the  lake  of  Geneva,  into  which  the  Rhone  flows 
laden  with  mud  and  comes  out  at  the  other  end  clear 
and  pure.  But  if  no  lake  lies  in  the  way  the  finer 
earth  will  still  travel  on,  and  the  river  v/ill  take  up 
more  and  more  as  it  flows,  till  at  last  it  will  leave  this 
too  on  the  plains  across  which  it  moves  sluggishly 
along,  or  will  deposit  it  at  its  mouth  when  it  joins  the 
sea. 

You  all  know  the  history  of  the  Nile  ;  how,  when  the 
rains  fall  very  heavily  in  March  and  April  in  the 
mountains  of  Abyssinia,  the  river  comes  rushing  down, 
and  brings  with  it  a  load  of  mud  which  it  spreads  out 
over  the  Nile  valley  in  Egypt.    This  annual  layer  ol 


114  THE  FAIRY-LAND  OF  SCIENCE. 


mud  is  so  thin  that  it  takes  a  thousand  years  for 
it  to  become  2  or  3  feet  thick  ;  but  besides  that  which 
falls  in  the  valley  a  great  deal  is  taken  to  the  mouth 
of  the  river  and  there  forms  new  land,  making  what  is 
called  the  Delta  of  the  Nile.  Alexandria,  Rosetta, 
and  Damietta,  are  towns  which  are  all  built  on  land 
made  of  Nile  mud  which  was  carried  down  ages  and 
ages  ago,  and  which  has  now  become  firm  and  hard 
like  the  rest  of  the  country.  You  will  easily  remember 
other  deltas  mentioned  in  books,  and  all  these  are 
made  of  the  mud  carried  down  from  the  land  to  the 
sea.  The  delta  of  the  Ganges  and  Brahmapootra  in 
India,  is  actually  as  large  as  the  whole  of  England  and 
Wales,*  and  the  River  Mississippi  in  America  drains 
such  a  large  tract  of  country  that  its  delta  grows, 
Mr.  Geikie  tells  us,  at  the  rate  of  86  yards  in  a  year. 

All  this  new  land  laid  down  in  Egypt,  in  India,  in 
America,  and  in  other  places,  is  the  work  of  water. 
Even  on  the  Thames  you  may  see  mud-banks,  as  at 
Gravesend,  which  are  made  of  earth  brought  from 
the  interior  of  England.  But  at  the  mouth  of  the 
Thames  the  sea  washes  up  very  strongly  every  tide, 
and  so  it  carries  most  of  the  mud  away  and  prevents 
a  delta  growing  up  there.  If  you  will  look  about  when 
you  are  at  the  seaside,  and  notice  wherever  a  stream 
flows  down  into  the  sea,  you  may  even  see  little 
miniature  deltas  being  formed  there,  though  the  sea 
generally  v/ashes  them  away  again  in  a  few  hours, 
unless  the  place  is  well  sheltered. 

This,  then,  is  what  becomes  of  the  earth  carried 
down  by  rivers.    Either  on  plains,  or  in  lakes,  or  in 

*  58,311  square  miles. 


THE  TWO  GREA  T  SCULPTORS.         •  1 1  5 

the  sea,  it  falls  down  to  form  new  land.  But  what 
becomes  of  the  dissolved  chalk  and  other  substances  ? 
We  have  seen  that  a  great  deal  of  it  is  used  by  river 
and  sea  animals  to  build  their  shells  and  skeletons, 
and  some  of  it  is  left  on  the  surface  of  the  ground  by 
springs  when  the  water  evaporates.  It  is  this  car- 
bonate of  lime  which  forms  a  hard  crust  over  any- 
thing upon  which  it  may  happen  to  be  deposited,  and 
then  these  things  are  called  petrified." 

But  it  is  in  the  caves  and  hollows  of  the  earth 
that  this  dissolved  matter  is  built  up  into  the  most 
beautiful  forms.  If  you  have  ever  been  to  Buxton  in 
Derbyshire,  you  will  probably  have  visited  a  cavern 
called  Poole's  Cavern,  not  far  from  there,  which  when 
you  enter  it  looks  as  if  it  were  built  up  entirely 
of  rods  of  beautiful  transparent  white  glass,  hanging 
from  the  ceiling,  from  the  walls,  or  rising  up  from  the 
floor.  In  this  cavern,  and  many  others  like  it,*  water 
comes  dripping  through  the  roof,  and  as  it  falls 
slowly  drop  by  drop  it  leaves  behind  a  little  of  the 
carbonate  of  lime  it  has  brought  out  of  the  rocks. 
This  carbonate  of  lime  forms  itself  into  a  thin,  white 
film  on  the  roof,  often  making  a  complete  circle,  and 
then,  as  the  water  drips  from  it  day  by  day,  it  goes  on 
growing  and  growing  till  it  forms  a  long  needle-shaped 
or  tube-shaped  rod,  hanging  like  an  icicle.  These  rods 
are  called  stalactites,  and  they  are  so  beautiful,  as  their 
minute  crystals  glisten  when  a  light  is  taken  into  the 
tavern,  that  one  of  them  near  Tenby  is  called  the 
"Fairy  Chamber.'*  Meanwhile,  the  water  which  drips 
on  to  the  floor  also  leaves  some  carbonate  of  lime 

®  See  the  picture  at  the  head  of  the  lecture. 


no 


THE  FAIRY-LAND  OF  SCIENCE. 


where  it  falls,  and  this  forms  a  pillar,  growing  up 
towards  the  roof,  and  often  the  hanging  stalactites 
and  the  rising  pillars  (called  stalagmites)  meet  in  the 
middle  and  form  one  column.  And  thus  we  see  that 
underground,  as  well  as  aboveground,  water  moulds 
beautiful  forms  in  the  crust  of  the  earth.  At  Adelsberg, 
near  Trieste,  there  is  a  magnificent  stalactite  grotto 
made  of  a  number  of  chambers  one  following  another, 
with  a  river  flowing  through  them  ;  and  the  famous 
Mammoth  Cave  of  Kentucky,  more  than  ten  miles 
long,  is  another  example  of  these  wonderful  limestone 
caverns. 

But  we  have  not  yet  spoken  of  the  sea,  and  this 
surely  is  not  idle  in  altering  the  shape  of  the  land. 
Even  the  waves  themselves  in  a  storm  wash  against 
the  cliffs  and  bring  down  stones  and  pieces  of  rock  on 
to  the  shore  below.  And  they  help  to  make  cracks 
and  holes  in  the  cliffs,  for  as  they  dash  with  force 
against  them  they  compress  the  air  which  lies  in 
the  joints  of  the  stone  and  cause  it  to  force  the  rock 
apart,  and  so  larger  cracks  are  made  and  the  cliff  is 
ready  to  crumble. 

It  is,  however,  the  stones  and  sand  and  pieces  of  rock 
lying  at  the  foot  of  the  cliff  which  are  most  active  in 
wearing  it  away.  Have  you  never  watched  the  waves 
breaking  upon  a  beach  in  a  heavy  storm  ?  How  they 
catch  up  the  stones  and  hurl  them  down  again,  grinding 
lliem  against  each  other!  At  high  tide  in  such  a 
storm  these  stones  are  thrown  against  the  foot  of  the 
cliff,  and  each  blow  does  something  towards  knocking 
away  part  of  the  rock,  till  at  last,  after  many  storms, 


THE  TWO  GREAT  SCULPTORS.  H? 

the  cliff  is  undermined  and  large  pieces  fall  down. 
These  pieces  are  in  their  turn  ground  down  to  pebbles 
which  serve  to  batter  against  the  remaining  rock. 

Professor  Geikie  tells  us  that  the  waves  beat  in  a 
storm  against  the  Bell  Rock  Lighthouse  with  as  much 
force  as  if  you  dashed  a  weight  of  3  tons  against 
every  square  inch  of  the  rock,  and  Stevenson  found 
stones  of  2  tons'  weight  which  had  been  thrown  during 
storms  right  over  the  ledge  of  the  lighthouse.  Think 
what  force  there  must  be  in  waves  which  can  lift  up 
such  a  rock  and  throw  it,  and  such  force  as  this  beats 
upon  our  sea-coasts  and  eats  away  the  land. 

Fig.  28. 


Cliffs  off  Arbroath,  showing  the  waste  of  the  shore. 

Fig.  28  is  a  sketch  on  the  shores  of  Arbroath  which 
1  m.ade  some  years  ago.    You  will  not  find  it  diffi- 


Il8  THE  FAIRY-LAND  OF  SCIENCE. 


cult  to  picture  to  yourselves  how  the  sea  has  eaten 
away  these  cliffs  till  some  of  the  strongest  pieces 
which  have  resisted  the  waves  stand  out  by  theai- 
selves  in  the  sea.  That  cave  in  the  left-hand  corner 
ends  in  a  narrow  dark  passage  from  which  you  come 
out  on  the  other  side  of  the  rocks  into  another  bay. 
Such  caves  as  these  are  made  chiefly  by  the  force  of 
the  waves  and  the  air,  bringing  down  pieces  of  rock 
from  under  the  cliff  and  so  making  a  cavity,  and  then 
as  the  waves  roll  these  pieces  over  and  over  and  grind 
them  against  the  sides,  the  hole  is  made  larger. 
There  are  many  places  on  the  English  coast  where 
large  pieces  of  the  road  are  destroyed  by  the  crumbling 
down  of  cliffs  when  they  have  been  undermined  by 
caverns  such  as  these. 

Thus,  you  see,  the  whole  of  the  beautiful  scenery  of 
the  sea — the  shores,  the  steep  cliffs,  the  quiet  bays,  the 
creeks  and  caverns — are  all  the  work  of  the  sculptor  " 
water ;  and  he  works  best  where  the  rocks  are  hardest, 
for  there  they  offer  him  a  good  stout  wall  to  batter, 
whereas  in  places  where  the  ground  is  soft  it  washes 
down  into  a  gradual  gentle  slope,  and  so  the  waves 
come  flowing  smoothly  in  and  have  no  power  to  eat 
away  the  shore. 

And  now,  what  has  Ice  got  to  do  with  the  sculp- 
turing of  the  land  \  First,  we  must  remember  how 
much  the  frost  does  in  breaking  up  the  ground.  The 
farmers  know  this,  and  always  plough  after  a  frost, 
because  the  moisture,  freezing  in  the  ground,  has 
broken  up  the  clods,  and  done  half  their  work  for 
them. 


THE  TWO  GREAT  SCULPTORS.  II9 

But  this  is  not  the  chief  work  of  ice.  You  will 
remember  how  we  learnt  in  our  last  lecture  that  snow, 
when  it  falls  on  the  mountains,  gradually  slides  down 
into  the  valleys,  and  is  pressed  together  by  the 
gathering  snow  behind  until  it  becomes  moulded  into 
a  solid  river  of  ice  (see  Fig.  29,  Frontispiece).  In 
Greenland  and  in  Norway  there  are  enormous  ice- 
rivers  or  glaciers,  and  even  in  Switzerland  some  of 
them  are  very  large.  The  Aletsch  glacier,  in  the 
Alps,  is  fifteen  miles  long,  and  some  are  even  longer 
than  this.  They  move  very  slowly — on  an  average 
about  20  to  27  inches  in  the  centre,  and  13  to 
19  inches  at  the  sides  every  twenty-four  hours,  in 
summer  and  autumn.  How  they  move,  we  cannot 
stop  to  discuss  now  ;  but  if  you  will  take  a  slab  of 
thin  ice  and  rest  it  upon  its  two  ends  only,  you  can 
prove  to  yourself  that  ice  does  bend,  for  in  a  few 
hours  you  will  find  that  its  own  weight  has  drawn  it 
down  in  the  centre  so  as  to  form  a  curve.  This  will 
help  you  to  picture  to  yourselves  how  glaciers  can 
adapt  themselves  to  the  windings  of  the  valley, 
creeping  slowly  onwards  until  they  come  down  to  a 
point  where  the  air  is  warm  enough  to  melt  them,  and 
then  the  ice  flows  away  in  a  stream  of  water.  It  is 
very  curious  to  see  the  number  of  little  rills  running 
down  the  great  masses  of  ice  at  the  glacier's  mouth, 
bringing  down  with  them  gravel,  and  every  now  and 
then  a  large  stone,  which  falls  splashing  into  the  stream 
below.  If  you  look  at  the  glacier  in  the  Frontispiece, 
you  will  see  that  these  stones  come  from  those  long 
lines  of  stones  and  boulders  stretching  along  the  sides 
and  centre  of  the  glacier.  It  is  easy  to  understand 
9 


120 


THE  FAIRY-LAND  OF  SCIENCE. 


where  the  stones  at  the  side  come  from  ;  for  we  have 
seen  that  damp  and  frost  cause  pieces  to  break  off 
the  surface  of  the  rocks,  and  it  is  natural  that  these 
pieces  should  roll  down  the  steep  sides  of  the  moun~ 
tains  on  to  the  glacier.  But  the  middle  row  requires 
some  explanation.  Look  to  the  back  of  the  picture, 
and  you  will  see  that  this  line  of  stones  is  made  of 
two  side  rows,  which  come  from  the  valleys  above. 
Two  glaciers,  you  see,  have  there  joined  into  one,  and  so 
made  a  heap  of  stones  all  along  their  line  of  junction. 

These  stones  are  being  continually,  though  slowly, 
conveyed  by  the  glacier,  from  all  the  mountains  along 
its  sides,  down  to  the  place  where  it  melts.  Here  it 
lets  them  fall,  and  they  are  gradually  piled  up  till 
they  form  great  walls  of  stone,  which  are  called 
moraines.  Some  of  the  moraines  left  by  the  larger 
glaciers  of  olden  time,  in  the  country  near  Turin,  form 
high  hills,  rising  up  even  to  1500  feet. 

Therefore,  if  ice  did  no  more  than  carry  these  stone 
blocks,  it  would  alter  the  face  of  the  country  ;  but  it 
does  much  more  than  this.  As  the  glacier  moves 
along,  it  often  cracks  for  a  considerable  way  across 
its  surface,  and  this  crack  widens  and  widens,  until  at 
last  it  becomes  a  great  gaping  chasm,  or  crevasse  as  it 
is  called,  so  that  you  can  look  down  it  right  to  the 
bottom  of  the  glacier.  Into  these  crevasses  large 
blocks  of  rock  fall,  and  when  the  chasm  is  closed 
again  as  the  ice  presses  on,  these  masses  are  frozen 
firmly  into  the  bottom  of  the  glacier,  much  in  the 
same  way  as  a  steel  cutter  is  fixed  in  the  bottom  of  a 
plane.  And  they  do  just  the  same  kind  of  work  ;  for 
as  the  glacier  slides  down  the  valley,  they  scratch  and 


THE  TWO  GREAT  SCULPTORS, 


121 


grind  the  rocks  underneath  them,  rubbing  themselves 
away,  it  is  true,  but  also  scraping  away  the  ground 
over  which  they  move.  In  this  way  the  glacier 
becomes  a  cutting  instrument,  and  carves  out  the 
valleys  deeper  and  deeper  as  it  passes  through  them. 

You  may  always  know  where  a  glacier  has  been, 
even  if  no  trace  of  ice  remains  ;  for  you  will  see  rocks 
with  scratches  along  them  which  have  been  cut  by 
these  stones  ;  and  even  where  the  rocks  have  not  been 
ground  away,  you  will  find  them  rounded  like  those  in 
the  left-hand  of  the  Frontispiece,  showing  that  the 
glacier-plane  has  been  over  them.  These  rounded 
rocks  are  called  roches  moutonnees,"  because  at  the 
distance  they  look  like  sheep  lying  down. 

You  have  dnly  to  look  at  the  stream  flowing  from 
the  mouth  of  a  glacier  to  see  what  a  quantity  of  soil 
it  has  ground  off  from  the  bottom  of  the  valley ;  for 
the  water  is  thick,  and  coloured  a  deep  yellow  by  the 
mud  it  carries.  This  mud  soon  reaches  the  rivers 
into  which  the  streams  run  ;  and  such  rivers  as  the 
Rhone  and  the  Rhine  are  thick  wath  matter  brought 
down  from  the  Alps.  The  Rhone  leaves  this  mud  in 
the  Lake  of  Geneva,  flowing  out  at  the  other  end  quite 
clear  and  pure.  A  mile  and  a  half  of  land  has  been 
formed  at  the  head  of  the  lake  since  the  time  of  the 
Romans  by  the  mud  thus  brought  down  from  the 
mountains. 

Thus  we  see  that  ice,  like  water,  is  always  busy 
carving  out  the  surface  of  the  earth,  and  sending  down 
m.aterial  to  make  new  land  elsewhere.  We  know  that 
in  past  ages  the  glaciers  were  much  larger  than  they 
are  in  our  time  ;  for  we  find  traces  of  them  over  large 


122  THE  FAIRY-LAND  OF  SCIENCE. 


parts  of  Switzerland  where  glaciers  do  not  now  exist, 
and  huge  blocks  which  could  only  have  been  carried 
by  ice,  and  which  are  called  erratic  blocks,"  some  of 
them  as  big  as  cottages,  have  been  left  scattered  over 
all  the  northern  part  of  Europe.  These  blocks  were 
a  great  puzzle  to  scientific  men  till,  in  1840,  Professor 
Agassiz  showed  that  they  must  have  been  brought  by 
ice  all  the  way  from  Norway  and  Russia. 

In  those  ancient  days,  there  were  even  glaciers  in 
England  ;  for  in  Cumberland  and  in  Wales  you  may 
see  their  work,  in  scratched  and  rounded  rocks,  and 
the  moraines  they  have  left.  Llanberis  Pass,  so 
famous  for  its  beauty,  is  covered  with  ice-scratches, 
and  blocks  are  scattered  all  over  the  sides  of  the 
valley.  There  is  one  block  high  up  on  the  right-hand 
slope  of  the  valley,  as  you  enter  from  the  Beddgelert 
side,  which  is  exactly  poised  upon  another  block,  so 
that  it  rocks  to  and  fro.  It  must  have  been  left  thus 
balanced  when  the  ice  melted  round  it.  You  may 
easily  see  that  these  blocks  were  carried  by  ice,  and 
not  by  water,  because  their  edges  are  sharp,  whereas, 
if  they  had  been  rolled  in  water,  they  would  have 
been  smoothed  down. 

We  cannot  here  go  into  the  history  of  that  great 
Glacial  Period  long  ago,  when  large  fields  of  ice 
covered  all  the  north  of  England ;  but  v/hen  you 
read  it  for  yourselves  and  understand  the  changes  on 
the  earth's  surface  which  we  can  see  being  made  by 
ice  now,  then  such  grand  scenery  as  the  rugged 
valleys  of  Wales,  with  large  angular  stone  blocks 
scattered  over  them,  will  tell  you  a  wonderful  story 
of  the  ice  of  bygone  times. 


THE  TWO  GREAT  SCULPTORS.  1 23 


And  now  we  have  touched  lightly  on  the  chief 
ways  in  which  water  and  ice  carve  out  the  surface 
of  the  earth.  We  have  seen  that  rain,  rivers,  springs, 
the  waves  of  the  sea,  frost,  and  glaciers  all  do  their 
part  in  chiselling  out  ravines  and  valleys,  and  in  pro- 
ducing rugged  peaks  or  undulating  plains  —  here 
cutting  through  rocks  so  as  to  form  precipitous  cliffs, 
there  laying  down  new  land  to  add  to  the  flat  country 
— in  one  place  grinding  stones  to  powder,  in  others 
piling  them  up  in  gigantic  ridges.  We  cannot  go  a 
step  into  the  country  without  seeing  the  work  of  water 
around  us  ;  every  little  gully  and  ravine  tells  us  that 
the  sculpture  is  going  on  ;  every  stream,  with  its 
burden  of  visible  or  invisible  matter,  reminds  us  that 
some  earth  is  being  taken  away  and  carried  to  a  new 
spot.  In  our  little  lives  we  see  indeed  but  very  small 
changes,  but  by  these  we  learn  how  greater  ones  have 
been  brought  about,  and  how  we  owe  the  outline  of 
all  our  beautiful  scenery,  with  its  hills  and  valleys, 
its  mountains  and  plains,  its  cliffs  and  caverns,  its 
quiet  nooks  and  its  grand  rugged  precipices,  to  the 
work  of  the    Two  great  sculptors,  Water  and  Ice." 


THE  FAIRY-LAND  OF  SCIENCE. 


LECTURE  VI. 

THE  VOICES  OF  NATURE  AND  HOW  WE  HEAR  THEM 


to-day  the  mid- 
dle point  of  our  course,  and  here  we  will  make  a 
new  start.  All  the  wonderful  histories  which  we 
have  been  studying  in  the  last  five  lectures  have  had 


THE  VOICES  OF  NA  TURE. 


125 


little  or  nothing  to  do  with  living  creatures.  The 
sunbeams  would  strike  on  our  earth,  the  air  would 
move  restlessly  to  and  fro,  the  water-drops  would  rise 
and  fall,  the  valleys  and  ravines  would  still  be  cut 
out  by  rivers,  if  there  were  no  such  thing  as  life  upon 
the  earth.  But  without  living  things  there  could  be 
none  of  the  beauty  which  these  changes  bring  about. 
Without  plants,  the  sunbeams,  the  air  and  the  water 
would  be  quite  unable  to  clothe  the  bare  rocks,  and 
without  animals  and  man  they  could  not  produce 
light,  or  sound,  or  feeling  of  any  kind. 

In  the  next  five  lectures,  however,  we  are  going  to 
learn  something  of  the  use  living  creatures  make  of 
the  earth  ;  and  to-day  we  will  begin  by  studying  one 
of  the  ways  in  which  we  are  affected  by  the  changes 
of  nature,  and  hear  her  voice. 

We  are  all  so  accustomed  to  trust  to  our  sight  to 
guide  us  in  most  of  our  actions,  and  to  think  of  things 
as  we  see  them,  that  we  often  forget  how  very  much 
we  owe  to  sound.  And  yet  Nature  speaks  to  us  so 
much  by  her  gentle,  her  touching,  or  her  awful  sounds, 
that  the  life  of  a  deaf  person  is  even  more  hard  to 
bear  than  that  of  a  blind  one. 

Have  you  ever  amused  yourself  with  trying  how 
many  different  sounds  you  can  distinguish  if  you 
listen  at  an  open  window  in  a  busy  street  i  You  will 
probably  be  able  to  recognize  easily  the  jolting  of  the 
heavy  waggon  or  dray,  the  rumble  of  the  omnibus,  the 
smooth  roll  of  the  private  carriage  and  the  rattle  of  the 
light  butcher's  cart ;  and  even  while  you  are  listening 
for  these,  the  crack  of  the  carter's  whip,  the  cry  of  the 
costermonger  at  his  stall,  and  the  voices  of  the  passers 


126 


THE  FAIRY-LAND  OF  SCIENCE, 


by  will  strike  upon  your  ear.  Then  if  you  give  still 
more  close  attention  you  will  hear  the  doors  open  and 
shut  along  the  street,  the  footsteps  of  the  passengers, 
the  scraping  of  the  shovel  of  the  mud-carts  ;  nay,  if 
he  happen  to  stand  near,  you  may  even  hear  the 
jingling  of  the  shoeblack's  pence  as  he  plays  pitch 
and  toss  upon  the  pavement.  If  you  think  for  a 
moment,  does  it  not  seem  wonderful  that  you  should 
hear  all  these  sounds  so  that  you  can  recognize  each 
one  distinctly  while  all  the  rest  are  going  on  around 
you  ? 

But  suppose  you  go  into  the  quiet  country. 
Surely  there  will  be  silence  there.  Try  some  day 
and  prove  it  for  yourself,  lie  down  on  the  grass  in 
a  sheltered  nook  and  listen  attentively.  If  there 
be  ever  so  little  wind  stirring  you  will  hear  it  rustling 
gently  through  the  trees  ;  or  even  if  there  is  not  this, 
it  will  be  strange  if  you  do  not  hear  some  wandering 
gnat  buzzing,  or  some  busy  bee  humming  as  it  moves 
from  flower  to  flower.  Then  a  grasshopper  will  set 
up  a  chirp  within  a  few  yards  of  you,  or,  if  all  living 
creatures  are  silent,  a  brook  not  far  off*  may  be  flowing 
along  with  a  rippling  musical  sound.  These  and  a 
hundred  other  noises  you  will  hear  in  the  most  quiet 
country  spot ;  the  lowing  of  cattle,  the  song  of  the  birds, 
the  squeak  of  the  field-mouse,  the  croak  of  the  frog, 
mingling  with  the  sound  of  the  woodman's  axe  in  the 
distance,  or  the  dash  of  some  river  torrent.  And 
besides  these  quiet  sounds,  there  are  still  other  occa- 
sional voices  of  nature  which  speak  to  us  from  time 
to  time.  The  howling  of  the  tempestuous  wind,  the 
roar  of  the  sea-weaves  in  a  storm,  the  crash  of  thunder, 


THE  VOICES  OF  NA  TURE. 


127 


and  the  mighty  noise  of  the  falling  avalanche  ;  such 
sounds  as  these  tell  us  how  great  and  terrible  nature 
can  be. 

Now,  has  it  ever  occurred  to  you  to  think  what 
sound  is,  and  how  it  is  that  we  hear  all  these  things  ? 
Strange  as  it  may  seem,  if  there  were  no  creature  that 
could  hear  upon  the  earth,  there  would  be  no  such 
thing  as  sound,  though  all  these  movements  in  nature 
were  going  on  just  as  they  are  now. 

Try  and  grasp  this  thoroughly,  for  it  is  difficult  at 
first  to  make  people  believe  it.  Suppose  you  were 
stone-deaf,  there  would  be  no  such  thing  as  sound  to 
you.  A  heavy  hammer  falling  on  an  anvil  would 
indeed  shake  the  air  viv  lently,  but  since  this  air  when 
it  reached  your  ear  would  find  a  useless  instrument, 
it  could  not  play  upon  it.  And  it  is  this  play  on  the 
djntm  of  your  ear  a7td  the  nerves  within  it  speaking 
to  your  brain  which  makes  sound.  Therefore,  if  all 
creatures  on  or  around  the  earth  were  without  ears  or 
nerves  of  hearing,  there  would  be  no  instruments  on 
which  to  play,  and  consequently  there  would  be  no 
such  thing  as  sound.  This  proves  that  two  things 
are  needed  in  order  that  we  may  hear.  First,  the 
outside  movement  which  plays  on  our  hearing  instru- 
ment ;  and,  secondly,  the  hearing  instrument  itself. 

First,  then,  let  us  try  to  understand  what  happens 
outside  our  ears.  Take  a  poker  and  tie  a  piece  of 
string  to  it,  and  holding  the  ends  of  the  string  to  your 
ears,  strike  the  poker  against  the  fender.  You  will 
hear  a  very  loud  sound,  for  the  blow  will  set  all  the 
particles  of  the  poker  quivering,  and  this  movement 


128 


THE  FAIRY-LAND  OF  SCIENCE. 


will  pass  right  along  the  string  to  the  drum  of  your 
ear  and  play  upon  it. 

Now  take  the  string  away  from  your  ears,  and  hold 
it  with  your  teeth.  Stop  your  ears  tight,  and  strike 
the  poker  once  more  against  the  fender.  You  will 
hear  the  sound  quite  as  loudly  and  clearly  as  you  did 
before,  but  this  time  the  drum  of  your  ear  has  not 
been  agitated.  How,  then,  has  the  sound  been  pro- 
duced ?  In  this  case,  the  quivering  movement  has 
passed  through  your  teeth  into  the  bones  of  your  head, 
and  from  them  into  the  nerves,  and  so  produced  sound 
in  your  brain.  And  now,  as  a  final  experiment,  fasten 
the  string  to  the  mantelpiece,  and  hit  it  again  against 
the  fender.  How  much  feebler  the  sound  is  this  time, 
and  how  much  sooner  it  stops  !  Yet  still  it  reaches 
you,  for  the  movement  has  come  this  time  across  the 
air  to  the  drum  of  your  ear. 

Here  we  are  back  again  in  the  land  of  invisible 
workers !  We  have  all  been  listening  and  hearing 
ever  since  we  were  babies,  but  have  we  ever  made  any 
picture  to  ourselves  of  how  sound  comes  to  us  right 
across  a  room  or  a  field,  when  we  stand  at  one  end 
and  the  person  who  calls  is  at  the  other } 

Since  we  have  studied  the  "  aerial  ocean,"  we  know 
that  the  air  filling  the  space  between  us,  though  in- 
visible, is  something  very  real,  and  now  all  we  have  to 
do  is  to  understand  exactly  how  the  movement  crosses 
this  air. 

This  we  shall  do  most  readily  by  means  of  an 
experiment  made  by  Dr.  Tyndall  in  his  lectures  on 
Sound.  I  have  here  a  number  of  boxwood  balls 
resting  in  a  wooden  tray  which  has  a  bell  hung  at  the 


THE  VOICES  OF  NATURE.  1 29 


end  of  it.  I  am  going  to  take  the  end  ball  and  roll  it 
sharply  against  the  rest,  and  then  I  want  you  to 
notice  carefully  what  happens.  See !  the  ball  at  the 
other  end  has  flown  off  and  hit  the  bell,  so  that  you 
hear  it  ring.  Yet  the  other  balls  remain  where  they 
were  before.  Why  is  this  1  It  is  because  each  of  the 
balls,  as  it  was  knocked  forwards,  had  one  in  front  of 
it  to  stop  it  and  make  it  bound  back  again,  but  the 
last  one  was  free  to  move  on.  When  I  threw  this  ball 
from  my  hand  against  the  others,  the  one  in  front  of  it 
moved,  and  hitting  the  third  ball,  bounded  back 
again ;  the  third  did  the  same  to  the  fourth,  the  fourth 


to  the  fifth,  and  so  on  to  the  end  of  the  line.  Each 
ball  thus  came  back  to  its  place,  but  it  passed  the 
shock  on  to  the  last  ball,  and  the  ball  to  the  bell.  If  I 
now  put  the  balls  close  up  to  the  bell,  and  repeat  the 
experiment,  you  still  hear  the  sound,  for  the  last  ball 
shakes  the  bell  as  if  it  were  a  ball  in  front  of  it. 

Now  imagine  these  balls  to  be  atoms  of  air,  and  the 
bell  your  ear.  If  I  clap  my  hands  and  so  hit  the  air 
in  front  of  them,  each  air-atom  hits  the  next  just  as 
the  balls  did,  and  though  it  comes  back  to  its  place, 
it  passes  the  shock  on  along  the  whole  line  to  the 
atom  touching  the  drum  of  your  ear,  and  so  you 


I30  THE  FAIRY-LAND  OF  SCIENCE. 


receive  a  blow.  But  a  curious  thing  happens  in  the 
air  which  you  cannot  i\otice  in  the  balls.  You  must 
remember  that  air  is  elastic,  just  as  if  there  were 
springs  between  the  atoms  as  in  the  diagram,  Fig.  31, 
and  so  when  any  shock  knocks  the  atoms  forward, 
several  of  them  can  be  crowded  together  before  they 
push  on  those  in  front.  Then,  as  soon  as  they  have 
passed  the  shock  on,  they  rebound  and  begin  to 
separate  again,  and  so  swing  to  and  fro  till  they 
come  to  rest.  Meanwhile  the  second  set  will  go 
through  just  the  same  movements,  and  will  spring 
apart  as  soon  as  they  have  passed  the  shock  on  to  a 
third  set,  and  so  you  will  have  one  set  of  crowded 


fig.  31- 


A 


0-^-0  0 — - 0 # # # # — 0 — 0  0               — %  0 # 0 

B 


atoms  and  one  set  of  separated  atoms  alternately  all 
along  the  line,  and  the  same  set  will  never  be  crowded 
two  instants  together. 

You  may  see  an  excellent  example  of  this  in  a 
luggage  train  in  a  railway  station,  when  the  trucks  are 
left  to  bump  each  other  till  they  stop.  You  will  see 
three  or  four  trucks  knock  together,  then  they  will 
pass  the  shock  on  to  the  four  in  front,  while  they 
themselves  bound  back  and  separate  as  far  as  their 
chains  will  let  them  :  the  next  four  trucks  will  do  the 
same,  and  so  a  kind  of  wave  of  crowded  trucks  passes 
on  to  the  end  of  the  train,  and  they  bump  to  and  fro 
till  the  whcle  comes  to  a  standstill.  Try  to  imaofine  a 


THE  VOICES  OF  NA  TURE. 


movement  like  this  going  on  in  the  Hne  of  air-atoms, 
Fig.  31,  the  drum  of  your  ear  being  at  the  end  B. 
Those  which  are  crowded  together  at  that  end  will 
hit  on  the  drum  of  your  ear  and  drive  the  membrane 
which  covers  it  inwards  ;  then  instantly  the  wave  will 
change,  these  atoms  will  bound  back,  and  the  mem- 
brane will  recover  itself  again,  but  only  to  receive  a 
second  blow  as  the  atoms  are  driven  forwards  again, 
and  so  the  membrane  will  be  driven  in  and  out  till  the 
air  has  settled  down. 

This  you  see  is  quite  different  to  the  waves  of  light 
which  move  in  crests  and  hollows.    Indeed,  it  is  not 


Fig.  32. 


what  we  usually  understand  by  a  wave  at  all,  but 
a  set  of  crowdings  and  partings  of  the  atoms  of  air 
which  follow  each  other  rapidly  across  the  air.  A 
crowding  of  atoms  is  called  a  condensation^  and  a 
parting  is  called  a  rarefaction^  and  when  we  speak  of 
the  length  of  a  w^ave  of  sound,  we  mean  the  distance 
between  two  condensations,  a  a  Fig.  32,  or  between 
two  rarefactions,  b  b. 

Although  each  atom  of  air  moves  a  very  little  way 
forwards  and  then  back,  yet,  as  a  long  row  of  atoms 
may  be  crowded  together  before  they  begin  to  part,  a 
wave  is  often  very  long.  When  a  man  talks  in  an 
ordinary  bass  voice,  he  makes  sound-waves  from  8  to 


132 


THE  FAIRY-LAND  OF  SCIENCE. 


12  feet  long  ;  a  woman's  voice  makes  shorter  waves, 
from  2  to  4  feet  long,  and  consequently  the  tone  is 
higher,  as  we  shall  presently  explain. 

And  now  I  hope  that  some  one  is  anxious  to  as\' 
why,  when  I  clap  my  hands,  anyone  behind  me  or  at 
the  side,  can  hear  it  as  well  or  nearly  as  well  as  you 
who  are  in  front.  This  is  because  I  give  a  shock  to 
the  air  all  round  my  hands,  and  v^aves  go  out  on  all 
sides,  making  as  it  were  globes  of  crowdings  and 
partings  widening  and  widening  away  from  the  clap 
as  circles  widen  on  a  pond.  Thus  the  waves  travel 
behind  me,  above  me,  and  on  all  sides,  until  they  hit 
the  walls,  the  ceiling,  and  the  floor  of  the  room,  and 
wherever  you  happen  to  be,  they  hit  upon  your  ear. 

If  you  can  picture  to  yourself  these  waves  spreading 
out  in  all  directions,  you  will  easily  see  why  sound 
grows  fainter  at  the  distance.  Just  close  round  my 
hands  when  I  clap  them,  there  is  a  small  quantity  of 
air,  and  so  the  shock  I  give  it  is  very  violent,  but  as 
the  sound-waves  spread  on  all  sides  they  have  more 
and  more  air  to  move,  and  so  the  air-atoms  are 
shaken  less  violently  and  strike  with  less  force  on 
your  ear. 

If  we  can  prevent  the  sound-wave  from  spreading, 
then  the  sound  is  not  weakened.  The  Frenchman  Biot 
found  that  a  low  whisper  could  be  heard  distinctly  for 
a  distance  of  half  a  mile  through  a  tube,  because  the 
waves  could  not  spread  beyond  the  small  column  of 
air.  But  unless  you  speak  into  a  small  space  of  some 
kind,  you  cannot  prevent  the  waves  going  out  from 
you  in  all  directions. 

Try  and  imagine  that  you  see  these  waves  spreading 


THE  VOICES  OF  NA  TURE. 


all  round  me  now  and  hitting  on  your  ears  as  they 
pass,  then  on  the  ears  of  those  behind  you,  and  on 
and  on  in  widening  globes  till  they  reach  the  wall. 
What  will  happen  when  they  get  there  ?  If  the  wall 
were  thin,  as  a  wooden  partition  is,  they  would  shake 
it,  and  it  again  would  shake  the  air  on  the  other  side, 
and  so  anyone  in  the  next  room  would  have  the 
sound  of  my  voice  brought  to  their  ear. 

But  something  more  will  happen.  In  any  case 
the  sound-waves  hitting  against  the  wall  will  bound 
back  from  it  just  as  a  ball  bounds  back  when  thrown 
against  anything,  and  so  another  set  of  sound-waves 
reflected  from  the  wall  will  come  back  across  the 
room.  If  these  waves  come  to  your  ear  so  quickly  that 
they  mix  with  direct  waves,  they  help  to  make  the 
sound  louder.  For  instance,  if  I  say  Ha,"  you  hear 
that  sound  louder  in  this  room  than  you  would  in  the 
open  air,  for  the  "  Ha"  from  my  mouth  and  a  second 
"  Ha  "  from  the  wall  come  to  your  ear  so  instantane- 
ously that  they  make  one  sound.  This  is  why  you 
can  often  hear  better  at  the  far  end  of  a  church  when 
you  stand  against  a  screen  or  a  wall,  than  when  you 
are  half-way  up  the  building  nearer  to  the  speaker, 
because  near  the  wall  the  reflected  waves  strike 
strongly  on  your  ear  and  make  the  sound  louder. 

Sometimes,  when  the  sound  comes  from  a  great 
explosion,  these  reflected  waves  are  so  strong  that 
they  are  able  to  break  glass.  In  the  explosion  of 
gunpowder  in  St.  John's  Wood,  many  houses  in  the 
back  streets  had  their  windows  broken ;  for  the  sound- 
waves bounded  off  at  angles- from  the  walls  and  struck 
back  upon  them. 


134  THE  FAIRY-LAND  OF  SCIENCE. 


Now,  suppose  the  wall  were  so  far  behind  you  that 
the  reflected  sound-waves  only  hit  upon  your  ear  after 
those  coming  straight  from  me  had  died  away ;  then 
you  would  hear  the  sound  twice,  "  Ha  "  from  me  and 
**Ha"  from  the  wall,  and  here  you  have  an  echo, 
Ha,  ha."  In  order  for  this  to  happen  in  ordinary 
air,  you  must  be  standing  at  least  56  feet  away  from 
the  point  from  which  the  waves  are  reflected,  for  then 
the  second  blow  will  come  one-tenth  of  a  second  after 
the  first  one,  and  that  is  long  enough  for  you  to  feel 
them  separately.*  Miss.  C.  A.  Martineau  tells  a  story 
of  a  dog  which  was  terribly  frightened  by  an  echo. 
Thinking  another  dog  was  barking,  he  ran  forward  to 
meet  him,  and  was  very  much  astonished,  when,  as  he 
came  nearer  the  wall,  the  echo  ceased.  I  myself  once 
knew  a  case  of  this  kind,  and  my  dog,  when  he  could 
find  no  enemy,  ran  back  barking,  till  he  was  a  certain 
distance  off",  and  then  the  echo  of  course  began  again. 
He  grew  so  furious  at  last  that  we  had  great  diffi- 
culty in  preventing  him  from  flying  at  a  strange  man 
who  happened  to  be  passing  at  the  time. 

Sometimes,  in  the  mountains,  walls  of  rock  rise  at 
some  distance  one  behind  another,  and  then  each  one 
will  send  back  its  echo  a  little  later  than  the  rock  before 
it,  so  that  the  '*Ha"  which  you  give  will  come  back 
as  a  peal  of  laughter.  There  is  an  echo  in  Woodstock 
Park  which  repeats  the  word  twenty  times.  Again 
sometimes,  as  in  the  Alps,  the  sound-waves  in  coming 

♦  Sound  travels  11 20  feet  in  a  second,  in  air  of  ordinary  temperatnie, 
and  therefore  112  feet  in  the  tenth  of  a  second.  Therefore  the  journey 
of  56  feet  beyond  you  to  reach  the  wall  and  56  feet  to  return,  will 
occupy  the  sound-wave  one-tenih  of  a  second  and  separate  the  two 
gounds. 


THE  VOICES  OF  NATURE. 


back  rebound  from  mountain  to  mountain  and  are 
driven  backwards  and  forwards,  becoming  fainter  and 
fainter  till  they  die  away ;  these  echoes  are  very 
beautiful. 

If  you  are  now  able  to  picture  to  yourselves  one  set 
of  waves  going  to  the  wall,  and  another  set  returning 
and  crossing  them,  you  will  be  ready  to  understand 
something  of  that  very  difficult  question,  How  is  it 
that  we  can  hear  many  different  sounds  at  one  time 
and  tell  them  apart  ? 

Have  you  ever  watched  the  sea  when  its  surface  is 
much  ruffled,  and  noticed  how,  besides  the  big  waves 
of  the  tide,  there  are  numberless  smaller  ripples  made 
by  the  wind  blowing  the  surface  of  the  water,  or  the 
oars  of  a  boat  dipping  in  it,  or  even  rain-drops  falling  ? 
If  you  have  done  this  you  will  have  seen  that  all 
these  waves  and  ripples  cross  each  other,  and  you  can 
follow  any  one  ripple  with  your  eye  as  it  goes  on  its 
way  undisturbed  by  the  rest.  Or  you  may  make 
beautiful  crossing  and  recrossing  ripples  on  a  pond 
by  throwing  in  two  stones  at  a  little  distance  from 
each  other,  and  here  too  you  can  follow  any  one  wave 
on  to  the  edge  of  the  pond. 

Now  just  in  this  way  the  waves  of  sound,  in  their 
manner  of  moving,  cross  and  recross  each  other.  You 
will  remember  too,  that  different  sounds  make  waves 
of  different  lengths,  just  as  the  tide  makes  a  longwave 
and  the  rain-drops  tiny  ones.  Therefore  each  sound 
falls  with  its  own  peculiar  wave  upon  your  ear,  and 
you  can  listen  to  that  particular  wave  just  as  you  look 
at  one  particular  ripple,  and  then  the  sound  becomes 
clear  to  you. 


136  THE  FAIRY- LAND  OF  SCIENCE. 


All  this  is  what  is  going  on  outside  your  ear,  but 
what  is  happening  in  your  ear  itself  ?  How  do  these 
blows  of  the  air  speak  to  your  brain  ?  By  means  oi 
the  following  diagram,  Fig.  33,  we  will  try  to  under- 
stand roughly  our  beautiful  hearing  instrument,  th^ 
ear. 

Fig.  33. 


«,  Concha,  or  shell  of  the  ear.  be.  Auditory  canal.  ^,  Tympanic 
membrane  stretched  across  the  drum  of  the  ear.    E,  Eustachian  tube. 

e,  /,  ear-bones  :  d,  the  hammer,  malleus  ;  <f,  the  anvil,  incus ;  /,  the 
stirrup,  stapes.  L,  Labyrinth,  gy  Cochlea,  or  internal  spiral  shell. 
h.  One  of  the  little  windows  ;  the  other  is  covered  by  the  stirrup. 


First,  I  want  you  to  notice  how  beautifully  the  out- 
side  shell,  or  conclia  as  it  is  called  {a),  is  curved  round 
so  that  any  movement  of  the  air  coming  to  it  from 
the  front  is  caught  in  it  and  reflected  into  the  hole  of 
the  ear.  Put  your  finger  round  your  ear  and  feel  how 
the  gristly  part  is  curved  towards  the*  front  of  your 


THE  VOICES  OF  NATURE, 


head.  This  concha  makes  a  curve  much  like  the 
curve  a  deaf  man  makes  with  his  hand  behind  his  ear 
to  catch  the  sound.  Animals  often  have  to  raise  their 
ears  to  catch  the  sound  well,  but  ours  stand  always 
ready.  When  the  air-waves  have  passed  in  at  the 
hole  of  your  ear,  they  move  all  the  air  in  the  passage, 
be,  which  is  called  the  auditory,  or  hearing,  canal. 
This  canal  is  lined  with  little  hairs  to  keep  out  insects 
and  dust,  and  the  wax  which  collects  in  it  serves  the 
same  purpose.  But  if  too  much  wax  collects,  it  pre- 
vents the  air  from  playing  well  upon  the  drum,  and 
therefore  makes  you  deaf.  Across  the  end  of  this 
canal,  at  a  membrane  or  skin  called  the  tympanum 
is  stretched,  like  the  parchment  over  the  head  of  a 
drum,  and  it  is  this  membrane  which  moves  to  and 
fro  as  the  air-waves  strike  on  it  A  violent  box 
on  the  ear  will  sometimes  break  this  delicate  mem- 
brane, or  injure  it,  and  therefore  it  is  very  wrong  to 
hit  a  person  violently  on  the  ear. 

On  the  other  side  of  this  membrane,  inside  the  ear, 
there  is  air,  which  fills  the  whole  of  the  inner  chamber 
and  the  tube  E,  which  runs  down  into  the  throat  behind 
the  nose,  and  is  called  the  Eustachian  tube  after  the 
man  who  discovered  it.  This  tube  is  closed  at  the 
end  by  a  valve  which  opens  and  shuts.  If  you  breathe 
out  strongly,  and  then  shut  your  mouth  and  swallow, 
you  will  hear  a  little  click  "  in  your  ear.  This  is 
because  in  swallowing  you  draw  the  air  out  of  the 
Eustachian  tube  and  so  draw  in  the  membranes,  which 
clicks  as  it  goes  back  again.  But  unless  you  do  this 
the  tube  and  the  whole  chamber  cavity  behind  the 
membrane  remains  full  of  air. 


138  THE  FAIRY-LAND  OF  SCIENCE. 


Now,  as  this  membrane  is  driven  to  and  fro  by  the 
sound-waves,  it  naturally  shakes  the  air  in  the  cavity 
behind  it,  and  it  also  sets  moving  three  most  curious 
little  bones.  The  first  of  these  bones  d  is  fastened 
to  the  middle  of  the  drumhead  so  that  it  moves  to 
and  fro  every  time  this  membrane  quivers.  The  head 
of  this  bone  fits  into  a  hole  in  the  next  bone  the 
anvil,  and  is  fastened  to  it  by  muscles,  so  as  to  drag  it 
along  with  it ;  but,  the  muscles  being  elastic,  it  can 
draw  back  a  little  from  the  anvil,  and  so  give  it  a  blow 
each  time  it  comes  back.  This  anvil,  e  is  in  its  turn 
very  firmly  fixed  to  the  little  bone  /,  shaped  like  a 
stirrup,  which  you  see  at  the  end  of  the  chain. 

This  stirrup  rests  upon  a  curious  body  L,  which 
looks  in  the  diagram  like  a  snail-shell  with  tubes 
coming  out  of  it.  This  body,  which  is  called  the 
labyrinth,  is  made  of  bone,  but  it  has  two  little 
w^indows  in  it,  one  h  covered  only  by  a  membrane, 
while  the  other  has  the  head  of  the  stirrup  /  resting 
upon  it. 

Now,  with  a  little  attention  you  will  understand 
that  when  the  air  in  the  canal  be  shakes  the  drum- 
head c  to  and  fro,  this  membrane  must  drag  with  it 
the  hammer,  the  anvil,  and  the  stirrup.  Each  time 
the  drum  goes  in,  the  hammer  will  hit  the  anvil,  and 
drive  the  stirrup  against  the  little  window ;  every  time 
it  goes  out  it  will  draw  the  hammer,  the  anvil,  and  the 
stirrup  out  again,  ready  for  another  blow.  Thus  the 
stirrup  is  always  playing  upon  this  little  window. 
Meanwhile,  inside  the  bony  labyrinth  L  there  is  a 
fluid  like  water,  and  along  the  little  passages  are 
very  fine  hairs,  which  wave  to  and  fro  like  reeds ;  and 


THE  VOICES  OF  NA  TURK, 


whenever  the  stirrup  hits  at  the  little  window,  the 
fluid  moves  these  hairs  to  and  fro,  and  they  irritate 
the  ends  of  a  nerve  and  this  nerve  carries  the  mes- 
sage to  your  brain.  There  are  also  some  curious  little 
stones  called  otoliths,  lying  in  some  parts  of  this  fluid, 
and  they,  by  their  rolling  to  and  fro,  probably  keep  up 
the  motion  and  prolong  the  sound. 

You  must  not  imagine  we  have  explained  here  the 
many  intricacies  which  occur  in  the  ear  ;  I  can  only 
hope  to  give  you  a  rough  idea  of  it,  so  that  you  may 
picture  to  yourselves  the  air-waves  moving  (as  in 
Fig.  32)  backwards  and  forward  in  the  canal  of  your 
ear,  then  the  tympanum  vibrating  to  and  fro,  the 
hammer  hitting  the  anvil,  the  stirrup  knocking  at  the 
little  window,  the  fluid  waving  the  fine  hairs  and  rolling 
the  tiny  stones,  the  ends  of  the  nerve  quivering,  and 
then  \  how  we  know  not)  the  brain  hearing  the  message. 

Is  not  this  wonderful,  going  on  as  it  does  at  every 
sound  you  hear  }  And  yet  this  is  not  all,  for  inside 
that  curled  part  of  the  labyrinth  which  looks  like  a 
snail-shell  and  is  called  the  cochlea^  there  is  a  most 
wonderful  apparatus  of  more  than  three  thousand  fine 
stretched  filaments  or  threads,  and  these  act  like  the 
strings  of  a  harp,  and  make  you  hear  different  tones. 
If  you  go  near  to  a  harp  or  a  piano,  and  sing  any 
particular  note  very  loudly,  you  will  hear  this  note 
sounding  in  the  instrument,  because  you  will  set  just 
that  particular  string  quivering,  which  gives  the  note 
yoj  sang.  The  air-waves  set  going  by  your  voice 
touch  that  string,  because  it  can  quiver  in  time  with 
them,  while  none  of  the  other  strings  can  do  so.  Now, 
just  in  the  same  way  the  tiny  instrument  of  three 


I40  THE  FAIRY-LAND  OF  SCIENCE. 


thousand  strings  in  your  ear,  which  is  called  Corti's 
organ,  vibrates  to  the  air-waves,  one  thread  to  one  set 
of  waves,  and  another  to  another,  and  according  to 
the  fibre  that  quivers,  will  be  the  sound  you  hear. 
Here  then  at  last,  we  see  how  nature  speaks  to  us. 
All  the  movements  going  on  outside,  however  violent 
and  varied  they  may  be,  cannot  of  themselves  make 
sound.  But  here,  in  the  little  space  behind  the  drum 
of  our  ear,  the  air-waves  are  sorted  and  sent  on  to 
our  brain,  where  they  speak  to  us  as  sound. 

But  why  then  do  we  not  hear  all  sounds  as  music  ? 
Why  are  some  mere  noise,  and  others  clear  musical 
notes  ?  This  depends  entirely  upon  whether  the  sound- 
waves come  quickly  and  regularly,  or  by  an  irregular 
succession  of  shocks.  For  example,  when  a  load  of 
stones  is  being  shot  out  of  a  cart,  you  hear  only  a  long, 
continuous  noise,  because  the  stones  fall  irregularly, 
some  quicker,  some  slower,  here  a  number  together, 
and  there  two  or  three  stragglers  by  themselves  ;  each 
of  these  different  shocks  comes  to  your  ear  and  makes 
a  confused,  noisy  sound.  But  if  you  run  a  stick  very 
quickly  along  a  paling,  you  will  hear  a  sound  very 
like  a  musical  note.  This  is  because  the  rods  of  the 
paling  are  all  at  equal  distances  one  from  the  other, 
and  so  the  shocks  fall  quickly  one  after  another  at 
regular  intervals  upon  your  ear.  Any  quick  and 
regular  succession  of  sounds  makes  a  note,  even 
though  it  may  be  an  ugly  one.  The  squeak  of  a  slate 
pencil  along  a  slate,  and  the  shriek  of  a  railway 
whistle  are  not  pleasant,  but  they  are  real  notes  which 
you  could  copy  on  a  violin. 


THE  VOICES  OF  NATURE, 


141 


I  have  here  a  simple  apparatus  which  I  have  had  made 
to  show  you  that  rapid  and  regular  shocks  produce  a 
natural  musical  note.  This  wheel  (Fig.  34)  is  milled  at 
the  edge  like  a  shilling,  and  when  I  turn  it  rapidly  so 
that  it  strikes  against  the  edge  of  the  card  fixed 
behind  it,  the  notches  strike  in  rapid  succession,  and 
produce  a  musical  sound.  We  can  also  prove  by 
this  experiment  that  the  quicker  the  blows  are,  the 
higher  the  note  will  be.    I  pull  the  string  gently  at 


first,  and  then  quicker  and  quicker,  and  you  will 
notice  that  the  note  grows  sharper  and  sharper, 
till  the  movement  begins  to  slacken,  when  the  note 
goes  down  again.  This  is  because  the  more  rapidly 
the  air  is  hit,  the  shorter  are  the  waves  it  makes,  and 
short  waves  give  a  high  note. 

Let  us  examine  this  with  two  tuning-forks.  I 
strike  one,  and  it  sounds  C,  the  third  space  in  the 
treble ;  I  strike  the  other,  and  it  sounds  the  first 
leger  line,  five  notes  above  the  C.  I  have  drawn  on  this 


Fig.  34. 


142  THE  FAIRY-LAND  OF  SCIENCE.  j 

diagram  (Fig.  35),  an  imaginary  picture  of  these  two 
sets  of  waves.  You  see  that  the  G  fork  makes  three 
waves,  while  the  C  fork  makes  only  two.  Why  is 
this  ?  Because  the  prong  of  the  G  fork  moves  three 
times  backwards  and  forwards  while  the  prong  of  the 
C  fork  only  moves  twice  ;  therefore  the  G  fork  does 
not  crowd  so  many  atoms  together  before  it  draws 
back,  and  the  waves  are  shorter.  These  two  notes,  C 
and  G,  are  a  fifth  of  an  octave  apart ;  if  we  had  two 

Fig.  35. 


fliJIMIi: 

liiiiiiiiii 

iiiiiiiiiiiiii 

forks,  of  which  one  went  twice  as  fast  as  the  other, 
making  four  waves  while  the  other  made  two,  then 
that  note  would  be  an  octave  higher. 

So  we  see  that  all  the  sounds  we  hear, — the  warning 
noises  which  keep  us  from  harm,  the  beautiful  musical 
notes  with  all  the  tunes  and  harmonies  that  delight 
us,  even  the  power  of  hearing  the  voices  of  those  we 
love,  and  learning  from  one  another  that  which  each 
can  tell, — all  these  depend  upon  the  invisible  waves  of 
air,  even  as  the  pleasures  of  light  depend  on  the  waves 
of  ether.     It  is  by  these  sound-waves  that  nature 


THE  VOICES  OF  NATURE. 


speaks  to  us,  and  in  all  her  movements  there  is  a 
reason  why  her  voice  is  sharp  or  tender,  loud  or 
gentle,  awful  or  loving.  Take  for  instance  the  brook 
we  spoke  of  at  the  beginning  of  the  lecture.  Why 
docs  it  sing  so  sweetly,  while  the  wide  deep  river 
makes  no  noise  1  Because  the  little  brook  eddies  and 
purls  round  the  stones,  hitting  them  as  it  passes ; 
sometimes  the  water  falls  down  a  large  stone,  and 
strikes  against  the  water  below ;  or  sometimes  it 
grates  the  little  pebbles  together  as  they  lie  in  its  bed. 
Each  of  these  blows  makes  a  small  globe  of  sound- 
waves, which  spread  and  spread  till  they  fall  on  your 
car,  and  because  they  fall  quickly  and  regularly,  they 
make  a  low,  musical  note.  We  might  almost  fancy 
that  the  brook  wished  to  show  how  joyfully  it  flows 
along,  recalling  Shelley's  beautiful  lines : — 

**  Sometimes  it  fell 
Among  the  moss  with  hollow  harmony, 
Dark  and  profound  ;  now  on  the  polished  stones 
It  danced ;  like  childhood  laughing  as  it  went." 

The  broad  deep  river,  on  the  contrary,  makes  none 
of  these  cascades  and  commotions.  The  only  places 
against  which  it  rubs  are  the  banks  and  the  bottom  ; 
and  here  you  can  sometimes  hear  it  grating  the  par- 
ticles of  sand  against  each  other  if  you  listen  very 
carefully.  But  there  is  another  reason  why  falling 
water  makes  a  sound,  and  often  even  a  loud  roaring 
noise  in  the  cataract  and  in  the  breaking  waves  of  the 
sea.  You  do  not  only  hear  the  water  dashing  against 
the  rocky  ledges  or  on  the  beach,  you  also  hear  the 
bursting  of  innumerable  little  bladders  of  air  which 
are  contained  in  the  water.  As  each  of  these  bladders 


144  THE  FAIRY-LAND  OF  SCIENCE. 


is  dashed  on  the  ground,  it  explodes  and  sends 
sound-waves  to  your  ear.  Listen  to  the  sea  some 
day  when  the  waves  are  high  and  stormy,  and  you 
cannot  fail  to  be  struck  by  the  irregular  bursts  of 
sound. 

The  waves,  however,  do  not  only  roar  as  they  dash 
on  the  ground  ;  have  you  never  noticed  how  they  seem 
to  scream  as  they  draw  back  down  the  beach  ?  Tenny- 
son calls  it, 

**  The  scream  of  the  madden'd  beach  dragged  down  by  the  wave 

and  it  is  caused  by  the  stones  grating  against  each 
other  as  the  waves  drag  them  down.  Dr.  Tyndall 
tells  us  that  it  is  possible  to  know  the  size  of  the 
stones  by  the  kind  of  noise  they  make.  If  they 
are  large,  it  is  a  confused  noise  ;  when  smaller,  a 
kind  of  scream  ;  while  a  gravelly  beach  will  produce  a 
mere  hiss. 

Who  could  be  dull  by  the  side  of  a  brook,  a  water- 
fall, or  the  sea,  while  he  can  listen  for  sounds  like  these, 
and  picture  to  himself  how  they  are  being  made  ?  You 
may  discover  a  number  of  other  causes  of  sound  made 
by  water,  if  you  once  pay  attention  to  them. 

Nor  is  it  only  water  that  sings  to  us.  Listen  to 
the  wind,  how  sweetly  it  sighs  among  the  leaves. 
There  we  hear  it,  because  it  rubs  the  leaves  together, 
and  they  produce  the  sound-waves.  But  walk  against 
the  wind  some  day  and  you  can  hear  it  whistling  in 
your  own  ear,  striking  against  the  curved  cup,  and 
then  setting  up  a  succession  of  waves  in  the  hearing 
canal  of  the  ear  itself. 

Why  should  it  sound  in  one  particular  tone  when 


THE  VOICES  OF  NA  TURE. 


145 


all  kinds  of  sound-waves  must  be  surging  about  in  the 
disturbed  air  ? 

This  glass  jar  will  answer  our  question  roughly.  If 
I  strike  my  tuning-fork  and  hold  it  over  the  jar,  you 
cannot  hear  it,  because  the  sound  is  feeble,  but  if  I 
fill  the  jar  gently  with  water,  when  the  water  rises 
to  a  certain  point  you  will  hear  a  loud  clear  note, 
because  the  waves  of 
air  in  the  jar  are  ex-  Fig.  36. 

actly  the  right  length 
to  answer  to  the  note 
of  the  fork.  If  I  now 
blow  across  the  mouth 
of  the  jar  you  hear 
the  same  note,  showing 
that  a  cavity  of  a  par- 
ticular length  will  only 
sound  to  the  waves 
which  fit  it.  Do  you 
see  now  the  reason 
why  pan-pipes  give  different  sounds,  or  even  the  hole 
at  the  end  of  a  common  key  when  you  blow  across 
it  ?  Here  is  a  subject  you  will  find  very  interesting 
if  you  will  read  about  it,  for  I  can  only  just  suggest 
it  to  you  here.  But  now  you  will  see  that  the  canal 
of  your  ear  also  answers  only  to  certain  waves,  and 
so  the  wind  sings  in  your  ear  with  a  real  if  not  a 
musical  note. 

Again,  on  a  windy  night  have  you  not  heard  the 
wind  sounding  a  wild,  sad  note  down  a  valley  ?  Why 
do  you  think  it  sounds  so  much  louder  and  more 
musical  here  than  when  it  is  blowing  across  the  plain  \ 


146  THE  FAIRY-LAND  OF  SCIENCE. 


Because  the  air  in  the  valley  will  only  answer  to  a 
certain  set  of  waves,  and,  like  the  pan-pipe,  gives  a 
particular  note  as  the  wind  blows  across  it,  and  these 
waves  go  up  and  down  the  valley  in  regular  pulses, 
making  a  wild  howl.  You  may  hear  the  same  in  the 
chimney,  or  in  the  keyhole  ;  all  these  are  waves  set  up 
in  the  hole  across  which  the  wind  blows.  Even  the 
music  in  the  shell  which  you  hold  to  your  ear  is  made 
by  the  air  in  the  shell  pulsating  to  and  fro.  And  how 
do  you  think  it  is  set  going  ?  By  the  throbbing  of  the 
veins  in  your  own  ear,  which  causes  the  air  in  the  shell 
to  vibrate. 

Another  grand  voice  of  nature  is  the  thunder. 
People  often  have  a  vague  idea  that  thunder  is  pro- 
duced by  the  clouds  knocking  together,  which  is  very 
absurd,  if  you  remember  that  clouds  are  but  water- 
dust.  The  most  probable  explanation  of  thunder  is 
much  more  beautiful  than  this.  You  will  remember 
from  Lecture  III.  that  heat  forces  the  air-atoms  apart. 
Now,  when  a  flash  of  lightning  crosses  the  sky  it 
suddenly  expands  the  air  all  round  it  as  it  passes,  so 
that  globe  after  globe  of  sound-waves  is  formed  at 
every  point  across  which  the  lightning  travels.  Now 
light,  you  remember,  travels  so  wonderfully  rapidly 
(192,000  miles  in  a  second)  that  a  flash  of  lightning  is 
seen  by  us  and  is  over  in  a  second,  even  when  it  is  two 
or  three  miles  long.  But  sound  comes  slowly,  taking 
five  seconds  to  travel  half  a  mile,  and  so  all  the  sound- 
waves at  each  point  of  the  two  or  three  miles  fall  on 
our  ear  one  after  the  other,  and  make  the  rolling 
thunder.  Sometimes  the  roll  is  made  even  longer 
by  the  echo,  as  the  sound-waves  are  reflected  to  and 


THE  VOICES  OF  NATURE. 


147 


fro  by  the  clouds  on  their  road;  and  in  the  mountains 
we  know  how  the  peals  echo  and  re-echo  till  they  die 
away. 

We  might  fill  up  far  more  than  an  hour  in  speaking 
of  those  voices  which  come  to  us  as  nature  is  at  work. 
Think  of  the  patter  of  the  rain,  how  each  dr©p  as  it 
hits  the  pavement  sends  circles  of  sound-waves  out  on 
ail  sides  ;  or  the  loud  report  which  falls  on  the  ear  of 
the  Alpine  traveller  as  the  glacier  cracks  on  its  way 
down  the  valley ;  or  the  mighty  boom  of  the  avalanche 
as  the  snow  slides  in  huge  masses  off  the  side  of  the 
lofty  mountain.  Each  and  all  of  these  create  their 
sound-waves,  large  or  small,  loud  or  feeble,  which 
make  their  way  to  your  ear,  and  become  converted 
into  sound. 

We  have,  however,  only  time  now  just  to  glance  at 
life-sounds,  of  which  there  are  so  many  around  us. 
Do  you  know  why  we  hear  a  buzzing,  as  the  gnat,  the 
bee,  or  the  cockchafer  fly  past }  Not  by  the  beating 
of  their  wings  against  the  air,  as  many  people  imagine, 
and  as  is  really  the  case  with  humming  birds,  but  by 
the  scraping  of  the  under-part  of  their  hard  wings 
against  the  edges  of  their  hind-legs,  which  are  toothed 
like  a  saw.  The  more  rapidly  their  wings  move  the 
stronger  the  grating  sound  becomes,  and  you  will  now 
see  why  in  hot,  thirsty  weather  the  buzzing  of  the  gnat 
is  so  loud,  for  the  more  thirsty  and  the  more  eager  he 
becomes,  the  wilder  his  movements  will  be. 

Some  insects,  like  the  drone-fly  (Eristalis  tenax), 
force  the  air  through  the  tiny  air-passages  in  their 
sides,  and  as  these  passages  are  closed  by  little  plates, 
the  plates  vibrate  to  and  fro  and  make  sound-waves. 


148 


THE  FAIRY-LAND  OF  SCIENCE. 


Again,  what  are  those  curious  sounds  you  may  hear 
sometimes  if  you  rest  your  head  on  a  trunk  in  the 
forest?  They  are  made  by  the  timber-boring  beetles, 
which  saw  the  wood  with  their  jaws  and  make  a  noise 
in  the  world,  even  though  they  have  no  voice. 

All  these  life-sounds  are  made  by  creatures  which 
do  not  sing  or  speak ;  but  the  sweetest  sounds  of  all 
in  the  woods  are  the  voices  of  the  birds.  All  voice- 
sounds  are  made  by  two  elastic  bands  or  cushions, 
called  vocal  chords,  stretched  across  the  end  of  the 
tube  or  windpipe  through  which  we  breathe,  and  as 
we  send  the  air  through  them  we  tighten  or  loosen 
them  as  we  will,  and  so  make  them  vibrate  quickly  or 
slowly  and  make  sound-waves  of  different  lengths. 
But  if  you  will  try  some  day  in  the  woods  you  will 
find  that  a  bird  can  beat  you  over  and  over  again  in 
the  length  of  his  note;  when  you  are  out  of  breath 
and  forced  to  stop  he  will  go  on  with  his  merry  trill 
as  fresh  and  clear  as  if  he  had  only  just  begun.  This 
is  because  birds  can  draw  air  into  the  whole  of  their 
body,  and  they  have  a  large  stock  laid  up  in  the  folds 
of  their  windpipe,  and  besides  this  the  air-chamber 
behind  their  elastic  bands  or  vocal  chords  has  two 
compartments  where  we  have  only  one,  and  the  second 
compartment  has  special  muscles  by  which  they  can 
open  and  shut  it,  and  so  prolong  the  trill. 

Only  think  what  a  rapid  succession  of  waves  must 
quiver  through  the  air  as  a  tiny  lark  agitates  his  little 
throat  and  pours  forth  a  volume  of  song !  The  next 
time  you  are  in  the  country  in  the  spring,  spend  half 
an  hour  listening  to  him,  and  try  and  picture  to 
yourself  how  that  little  being  is  moving  all  the  atmo- 


THE  VOICES  OF  NA  TV  RE. 


sphere  round  him.  Then  dream  for  a  little  while  about 
sound,  what  it  is,  how  marvellously  it  works  outside  in 
the  world,  and  inside  in  your  ear  and  brain  ;  and  then, 
when  you  go  back  to  work  again,  you  will  hardly 
deny  that  it  is  well  worth  while  to  listen  sometimes  to 
the  voices  of  nature  and  ponder  how  it  is  that  w^e  hear 
theia. 


ISO  THE  FAIRY-LAND  OF  SCIENCE. 


LECTURE  VII. 


THE  LIFE  OF  A  PRIMROSE. 


shine  has  begun  to  pour  down  upon  the  grassy  paths 
of  the  wood,  who  does  not  love  to  go  out  and  bring 
home  posies  of  violets,  and  bluebells,  and  prim- 
roses ?  We  wander  from  one  plant  to  another, 
picking  a  flower  here  and  a  bud  there,  as  they  nestle 


THE  LIFE  OF  A  PRIMROSE.  1 5 1 

among  the  green  leaves,  and  we  make  our  rooms 
sweet  and  gay  with  the  tender  and  lovely  blossoms. 
But  tell  me,  did  you  ever  stop  to  think,  as  you  added 
flower  after  flower  to  your  nosegay,  how  the  plants 
which  bear  them  have  been  building  up  their  green 
leaves  and  their  fragile  buds  during  the  last  few 
weeks  ?  If  you  had  visited  the  same  spot  a  month 
before,  a  few  last  year  s  leaves,  withered  and  dead, 
would  have  been  all  that  you  would  have  found.  And 
now  the  whole  wood  is  carpeted  with  delicate  green 
leaves,  with  nodding  bluebells,  and  pale-yellow  prim- 
roses, as  if  a  fairy  had  touched  the  ground  and  covered 
it  with  fresh  young  life.  And  our  fairies  have  been  at 
work  here  ;  the  fairy  "  Life,"  of  whom  we  know  so  little, 
though  we  love  her  so  well  and  rejoice  in  the  beautiful 
forms  she  can  produce ;  the  fairy  sunbeams  with  their 
invisible  influence  kissing  the  tiny  shoots  and  warming 
them  into  vigour  and  activity  ;  the  gentle  rain-drops, 
the  balmy  air,  all  these  have  been  working,  while  you 
or  I  passed  heedlessly  by  ;  and  now  we  come  and 
gather  the  flowers  they  have  made,  and  too  often 
forget  to  wonder  how  these  lovely  forms  have  sprung 
up  around  us. 

Our  work  during  the  next  hour  will  be  to  consider 
this  question.  You  were  asked  last  week  to  bring 
with  you  to-day  a  primrose-flower,  or  a  whole  plant  if 
possible,  in  order  the  better  to  follow  out  with  me  the 
"  Life  of  a  Primrose."  *  This  is  a  very  different  kind 
of  subject  from  those  of  our  former  lectures.  There 

*  To  enjoy  this  lecture,  the  child  ought  to  have,  if  possible,  a  prim- 
rose-flower, an  almond  soaked  for  a  few  minutes  in  hot  water,  and  f\ 
piece  of  orange. 


i52 


THE  FAIRY-LAND  OF  SCIENCE. 


we  took  world-wide  histories ;  we  travelled  up  to 
the  sun,  or  round  the  earth,  or  into  the  air ;  now  I 
only  ask  you  to  fix  your  attention  on  one  little  plant, 
and  inquire  into  its  history. 

There  is  a  beautiful  little  poem  by  Tennyson,  which 
says — 

**  Flower  in  the  crannied  wall, 
I  pluck  you  out  of  the  crannies  ; 
Hold  you  here,  root  and  all,  in  my  hand, 
Little  flower  ;  but  if  I  could  understand 
What  you  are,  root  and  all,  and  all  in  all, 
I  should  know  what  God  and  man  is." 

We  cannot  loarn  all  about  this  little  flower,  but  we 
can  learn  enough  to  understand  that  it  has  a  real 
separate  life  of  its  own,  well  worth  knowing.  For 
a  plant  is  born,  breathes,  sleeps,  feeds,  and  digests 
just  as  truly  as  an  animal  does,  though  in  a  dif- 
ferent way.  It  works  hard  both  for  itself  to  get  its 
food,  and  for  others  in  making  the  air  pure  and  fit 
for  animals  to  breathe.  It  often  lays  by  provision 
for  the  winter.  It  sends  young  plants  out,  as  parents 
send  their  children,  to  fight  for  themselves  in  the 
world  ;  and  then,  after  living  sometimes  to  a  good  old 
age,  it  dies,  and  leaves  its  place  to  others. 

We  will  try  to  follow  out  something  of  this  life  to- 
day ;  and  first,  we  will  begin  with  the  seed. 

I  have  here  a  packet  of  primrose-seeds,  but  they 
are  so  small  that  we  cannot  examine  them  ;  so  I  have 
also  had  given  to  each  one  of  you  an  almond-kernel, 
which  is  the  seed  of  the  almond-tree,  and  which  has 
been  soaked,  so  that  it  splits  in  half  easily.  From 
this  we  can  learn  about  seeds  in  general,  and  then 
apply  it  to  the  primrose. 


THE  LIFE  OF  A  PRIMROSE. 


Fig.  37. 


If  you  peel  the  two  skins  off  your  almond-seed  (the 
thick,  brown,  outside  skin,  and  the  thin,  transparent 
one  under  it),  the  two  halves  Of  the  almond  will 
slip  apart  quite  easily.    One  of  these 
halves  will  have  a  small  dent  at  the 
pointed  end,  vrhile  in  the  other  half 
you  will  see  a  little  lump,  which  fitted 
into  the  dent  when  the  two  halves  were 
joined.    This  little  lump  (a  b,  Fig.  37) 
is  a  young  plant,  and  the  two  halves  of 
the  almond  are  the  seed-leaves  which 
hold  the  plantlet,  and  feed  it  till  it 
can  feed  itself.    The  rounded  end  of  the 
plantlet  {b)  sticking  out  of  the  almond, 
is  the  beginning  of  the  root,  while  the 
other  end  (a)  will  in  time  become  the 
stem.    If  you  look  carefully,  you  will 
see  two  little  points  at  this  end,  which 
are  the  tips  of  future  leaves.    Only  think  how  minute 
this  plantlet  must  be  in  a  primrose,  where  the  whole 
seed  is  scarcely  larger  than  a  grain  of  sand !  Yet 
in  this  tiny  plantlet  lies  hid  the  life  of  the  future 
plant. 

When  a  seed  falls  into  the  ground,  so  long  as  the 
earth  is  cold  and  dry,  it  lies  like  a  person  in  a  trance, 
as  if  it  were  dead  ;  but  as  soon  as  the  warm,  damp 
spring  comes,  and  the  busy  little  sun-waves  pierce 
down  into  the  earth,  they  wake  up  the  plantlet,  and 
make  it  bestir  itself.  They  agitate  to  and  fro  the 
particles  of  matter  in  this  tiny  body,  and  cause  them 
:o  seek  out  for  other  particles  to  seize  and  join  to 
themselves. 


Half  an  almond, 
showing  the 
plantlet, 

rudiment  of 
stem.  ^,  begin- 
ning of  root. 


1 54  THE  FA  IR  Y'LAND  OF  SCIENCE. 


But  these  new  particles  cannot  come  in  at  the 
roots,  for  the  seed  has  none ;  nor  through  the  leaves, 
for  they  have  not  yet  grown  up  ;  and  so  the  plantlet 
begins  by  helping  itself  to  the  store  of  food  laid  up  in 
the  thick  seed-leaves  in  which  it  is  buried.  Here  it 
finds  starch,  oils,  sugar,  and  substances  called  albu- 
minoids,— the  sticky  matter  which  you  notice  in 
wheat-grains  when  you  chew  them  is  one  of  the 
albuminoids-  This  food  is  all  ready  for  the  plantlet 
to  use,  and  it  sucks  it  in,  and  works  itself  into  a 
young  plant  with  tiny  roots  at  one  end,  and  a  growing 
shoot,  with  leaves,  at  the  other. 

But  how  does  it  grow  }  What  makes  it  become 
larger  ?  To  answer  this,  you  must  look  at  the  second 
thing  I  asked  you  to  bring — a  piece  of  orange.  If 

you  take  the  skin  off  a 
piece  of  orange,  you  will 
see  inside  a  number  of  long- 
shaped  transparent  bags, 
full  of  juice.  These  we  call 
cells,  and  the  flesh  of  all 
plants  and  animals  is  made  up  of  cells  like  these, 
only  of  various  shapes.  In  the  pith  of  elder  they  are 
round,  large,  and  easily  seen  (a,  Fig.  39) ;  in  the 
stalks  of  plants  they  are  long,  and  lap  over  each 
other  {b,  Fig.  39),  so  as  to  give  the  stalk  strength  to 
stand  upriglit.  Sometimes  many  cells  growing  one 
on  the  top  of  the  other,  break  into  one  tube  and  make 
vessels.  But  whether  large  or  small,  they  are  all  bags 
growing  one  against  the  other. 

In  the  orange-pulp  these  cells  contain  only  sweet 
juice,  but  in  other,  parts  of  the  orange-tree  or  any 


Juicy  cells  in  a  piece  of  orange. 


THE  LIFE  OF  A  PRIMROSE.  1 55 


other  plant  they  contain  a  sticky  substance  with 
Httle  grains  in  it.  This  substance  is  called  "proto- 
plasm," or  the  first  form  of  life,  for  it  is  alive  and 
active,  and  under  a 
microscope  you  may 
see  in  a  living  plant 
streams  of  the  little 
grains  moving  about 
in  the  cells. 

Now  we  are  pre- 
pared to  explain  how 
our  plant  grows.  Ima- 
gine the  tiny  primrose 
plantlet  to  be  made  up 
o'f  cells  filled  with 
active  living  proto- 
plasm, which  drinks  in 
starch  and  other  food 
from  the  seed-leaves. 
In  this  way  each  cell  will  grow  too  full  for  its  skin, 
and  then  the  protoplasm  divides  into  two  parts 
and  builds  up  a  wall  between  them,  and  so  one  cell 
becomes  two.  Each  of  these  two  cells  again  breaks 
up  into  two  more,  and  so  the  plant  grows  larger  and 
larger,  till  by  the  time  it  has  used  up  all  the  food  in 
the  seed-leaves,  it  has  sent  roots  covered  with  fine 
hairs  downwards  into  the  earth,  and  a  shoot  with 
beginnings  of  leaves  up  into  the  air. 

Sometimes  the  seed-leaves  themselves  come  above 
ground,  as  in  the  mustard-plant,  and  sometimes  they 
are  left  empty  behind,  while  the  plantlet  shoots 
through  them. 


dz,  round  cells  in  pith  of  elder, 
long  cells  in  fibres  of  a  plant. 


156  THE  FAIRY-LAND  OF  SCIENCE. 


And  now  the  plant  can  no  longer  afford  to  be  idle 
and  live  on  prepared  food.  It  must  work  for  itself. 
Until  now  it  has  been  taking  in  the  same  kind  of 
food  that  you  and  I  do  ;  for  we  too  find  many  seeds 
very  pleasant  to  eat  and  useful  to  nourish  us.  But 
now  this  store  is  exhausted.  Upon  what  then  is  the 
plant  to  live  ?  It  is  cleverer  than  we  are  in  this,  for 
while  we  cannot  live  unless  we  have  food  which  has 
once  been  alive,  plants  can  feed  upon  gases  and  water 
and  mineral  matter  only.  Think  over  the  substances 
you  can  eat  or  drink,  and  you  will  find  they  are  nearly 
all  made  of  things  which  have  been  alive:  meat,  vege- 
tables, bread,  beer,  wine,  milk  ;  all  these  are  made  from 
living  matter,  and  though  you  do  take  in  such  things 
as  water  and  salt,  and  even  iron  and  phosphorus, 
these  would  be  quite  useless  if  you  did  not  eat  and 
drink  prepared  food  which  your  body  can  work  up 
into  living  matter. 

But  the  plant,  as  soon  as  it  has  roots  and  leaves, 
begins  to  make  living  matter  out  of  matter  that  has 
never  been  alive.  Through  all  the  little  hairs  of  its 
roots  it  sucks  in  water,  and  in  this  water  are  dissolved 
more  or  less  of  the  salts  of  ammonia,  phosphorus, 
sulphur,  iron,  lime,  magnesia,  and  even  silica,  or  flint. 
In  all  kinds  of  earth  there  is  some  iron,  and  we  shall 
see  presently  that  this  is  very  important  to  the  plant. 

Suppose,  then,  that  our  primrose  has  begun  to  drink 
in  water  at  its  roots.  How  is  it  to  get  this  water  up 
into  the  stem  and  leaves,  seeing  that  the  whole  plant 
is  made  of  closed  bags  or  cells  }  It  does  it  in  a  very 
curious  way,  which  you  can  prove  for  yourselves. 
Whenever  two  fluids,  one  thicker  than  the  other,  such 


THE  LIFE  OF  A  PRIMROSE.  157 


as  treacle  and  water  for  example,  are  only  separated 
by  a  skin  or  any  porous  substance,  they  will  always 
mix,  the  thinner  one  oozing  through  the  skin  into  the 
thicker  one.  If  you  tie  a  piece  of  bladder  over  a  glass 
tube,  fill  the  tube  half-full  of  treacle,  and  then  let 
the  covered  end  rest  in  a  bottle  of  water,  in  a  few 
hours  the  water  will  get  in  to  the  treacle  and  the 
mixture  will  rise  up  in  the  tube  till  it  flows  over  the 
top.  Now,  the  saps  and  juices  of  plants  are  thicker 
than  water,  so,  directly  the  water  enters  the  cells  at 
the  root  it  oozes  up  into  the  cells  above,  and  mixes 
with  the  sap.  Then  the  matter  in  those  cells  becomes 
thinner  than  in  the  cells  above,  so  it  too  oozes  up, 
and  in  this  way  cell  by  cell  the  water  is  pumped  up 
into  the  leaves. 

When  it  gets  there  it  finds  our  old  friends  the  sun- 
beams hard  at  work.  If  you  have  ever  tried  to  grow 
a  plant  in  a  cellar,  you  will  know  that  in  the  dark  its 
leaves  remain  white  and  sickly.  It  is  only  in  the 
sunlight  that  a  beautiful  delicate  green  tint  is  given 
to  them,  and  you  will  remember  from  Lecture  II.  that 
this  green  tint  shows  that  the  leaf  has  used  all  the 
sun-waves  except  those  which  make  you  see  green  ; 
but  why  should  it  do  this  only  when  it  has  grown  up 
in  the  sunshine  } 

The  reason  is  this :  when  the  sunbeam  darts  into 
the  leaf  and  sets  all  its  particles  quivering,  it  divides 
the  protoplasm  into  two  kinds,  collected  into  different 
cells.  One  of  these  remains  white,  but  the  other  kind, 
near  the  surface,  is  altered  by  the  sunlight  and  by  the 
help  of  the  iron  brought  in  by  the  water.  This  par- 
ticular kind  of  protoplasm,  which  is  called  "chloro 


IS8  THE  FAIRY-LAND  OF  SCIENCE. 


phyll,"  will  have  nothing  to  do  with  the  green  waves 
and  throws  them  back,  so  that  every  little  grain  of  this 
protoplasm  looks  green  and  gives  the  leaf  its  green 
colour. 

It  is  these  little  green  cells  that  by  the  help  of  the 
sun-waves  digest  the  food  of  the  plant  and  turn  the 
water  and  gases  into  useful  sap  and  juices.  We  saw 
in  Lecture  III.  that  when  we  breathe-in  air,  we  use 
up  the  oxygen  in  it  and  send  back  out  of  our  mouths 
carbonic  acid,  which  is  a  gas  made  of  oxygen  and 
carbon. 

Now,  every  living  thing  wants  carbon  to  feed  upon, 
but  plants  cannot  take  it  in  by  itself,  because  carbon 
is  solid  (the  blacklead  in  your  pencils  is  pure  carbon), 
and  a  plant  cannot  eat,  it  can  only  drink-in  fluids  and 
gases.  Here  the  little  green  cells  help  it  out  of  its 
difficulty.  They  take  in  or  absorb  out  of  the  air  the 
carbonic  acid  gas  which  we  have  given  out  of  our 
mouths,  and  then  by  the  help  of  the  sun-waves  they 
tear  the  carbon  and  oxygen  apart.  Most  of  the  oxygen 

they  throw  back  into 
the  air  for  us  to  use,  but 
the  carbon  they  keep. 

If  you  will  take  some 
fresh  laurel-leaves  and 
put  them  into  a  tumbler 
of  water  turned  upside- 
down    in   a    saucer  of 

Oxygen-bubbles  rising  from  laurel-     water,      and      set  the 

leaves  in  water.  tumbler  in  the  Sunshine, 

you  will  soon  see  little  bright  bubbles  rising  up 
\xxd  clinging  to  the  glass.     These  are  bubbles  of 


Fig.  40. 


THE  LIFE  OF  A  PRIMROSE.  159 


oxygen  gas,  and  they  tell  you  that  they  have  been 
set  free  by  the  green  cells  which  have  torn  from  them 
the  carbon  of  the  carbonic  acid  in  the  water. 

But  what  becomes  of  the  carbon  ?  And  what  use 
is  made  of  the  water  which  we  have  kept  waiting  all 
this  time  in  the  leaves  ?  Water,  you  already  know, 
is  made  of  hydrogen  and  oxygen  ;  but  perhaps  you 
will  be  surprised  when  I  tell  you  that  starch,  sugar, 
and  oil,  which  w^e  get  from  plants,  are  nothing  more 
than  hydrogen  and  oxygen  in  different  quantities 
joined  to  carbon. 

It  is  very  difficult  at  first  to  picture  such  a  black 
thing  as  carbon  making  part  of  delicate  leaves  and 
beautiful  flowers,  and  still  more  of  pure  white  sugar. 
But  we  can  make  an  experiment  by  which  we  can 
draw  the  hydrogen  and  oxygen  out  of  common  loaf 
sugar,  and  then  you  will  see  the  carbon  stand  out  in 
all  its  blackness.  I  have  here  a  plate  with  a  heap  of 
white  sugar  in  it.  I  pour  upon  it  first  some  hot 
water  to  melt  and  warm 
it,  and  then  some  strong  ^^^S-  4i- 

sulphuric  acid.    Tli'is  acid 
does  nothing  more  than 
simply  draw  the  hydrogen 
and  oxygen  out.    See  !  in    Carbon  rising  up  from  white  sugar 
a  few  moments  a  black 

mass  of  carbon  begins  to  rise,  all  of  which  has  come 
out  of  the  white  sugar  you  saw  just  now.*   You  see, 

*  The  common  dilute  sulphuric  acid  of  commerce  is  not  strong  enough 
for  this  experiment,  and  any  child  who  wants  to  get  pure  sulphuric 
Acid  must  take  some  elder  person  with  him,  otherwise  the  chemist  will 
not  sell  it  to  him.  Great  care  must  be  taken  in  using  it,  as  it  burns 
everything  it  touches. 


l6o  THE  FAIRY-LAND  OF  SCIENCE. 


then,  that  from  the  whitest  substance  in  plants  we 
can  get  this  black  carbon  ;  and  in  truth,  one-half  of 
the  dry  part  of  every  plant  is  composed  of  it. 

Now  look  at  my  plant  again,  and  tell  me  if  we 
have  not  already  found  a  curious  history  ?  Fancy 
that  you  see  the  water  creeping  in  at  the  roots,  oozing 
up  from  cell  to  cell  till  it  reaches  the  leaves,  and  there 
meeting  the  carbon  which  has  just  come  out  of  the 
air,  and  being  worked  up  with  it  by  the  sun-waves 
into  starch,  or  sugar,  or  oils. 

But  meanwhile,  how  is  new  protoplasm  to  be 
formed  "i  for  without  this  active  substance  none  of  the 
work  can  go  on.  Here  comes  into  use  a  lazy  gas 
we  spoke  of  in  Lecture  III.  There  we  thought  that 
nitrogen  was  of  no  use  except  to  float  oxygen  in  the 
air,  but  here  we  shall  find  it  very  useful.  So  far 
as  we  know,  plants  cannot  take  up  nitrogen  out  of 
the  air,  but  they  can  get  it  out  of  the  ammonia  which 
the  water  brings  in  at  their  roots. 

Ammonia,  you  will  remember,  is  a  strong-smelling 
gas,  made  of  hydrogen  and  nitrogen,  and  which  is 
often  almost  stifling  near  a  manure-heap.  When  you 
manure  a  plant  you  help  it  to  get  this  ammonia,  but 
at  any  time  it  gets  some  from  the  soil  and  also  from 
the  rain-drops  which  bring  it  down  in  the  air.  Out 
of  this  ammonia  the  plant  takes  the  nitrogen  and 
works  it  up  with  the  three  elements,  carbon,  oxygen, 
and  hydrogen,  to  make  the  substances  called  albumin 
noids,  which  form  a  large  part  of  the  food  of  the 
plant,  and  it  is  these  albuminoids  which  go  to  make 
protoplasm.  You  will  notice  that  while  the  starch 
and  oXh^r  substances  are  only  made  of  three  elements. 


THE  LIFE  OF  A  PRIMROSE.  I6l 


che  active  protoplasm  is  made  of  these  three  added 
to  a  fourth,  nitrogen,  and  it  also  contains  phosphorus 
and  sulphur. 

And  so  hour  after  hour  and  day  after  day  our 
primrose  goes  on  pumping  up  water  and  ammonia 
from  its  roots  to  its  leaves,  drinking  in  carbonic  acid 
from  the  air,  and  using  the  sun-waves  to  work  them 
all  up  into  food  to  be  sent  to  all  parts  of  its  body. 
In  this  way  these  leaves  act,  you  see,  as  the  stomach 
of  the  plant,  and  digest  its  food. 

Sometimes  more  water  is  drawn  up  into  the  leaves 
than  can  be  used,  and  then  the  leaf  opens  thousands 
of  little  mouths  in  the  skin  of  its  under  surface,  which 
let  the  drops  out  just  as  drops  of  perspiration  ooze 
throu2fh  our  skin  when  we  are  over- 
heated.   These  little  mouths,  which  * 
are  called  stomates  {a,  Fig.  42)  are  / 
made  of  two  flattened  cells,  fitting  (^^^^^^^5^^ 
against  each  other.    When  the  air  jM^®^^ 
is  damp  and  the  plant  has  too    a — 4^^^^^^^^ 
much  water  these  lie  open  and  let 
it  out,  but  when  the  air  is  dry,  and    c-.  ^  c 

Stomates  of  a  leaf. 

the  plant  wants  to  keep  as  much 
water  as  it  can,  then  they  are  closely  shut.  There 
are  as  many  as  a  hundred  thousand  of  these  mouths 
under  one  apple-leaf,  so  you  may  imagine  how  small 
ihey  often  are. 

Plants  which  only  live  one  year,  such  as  migno« 
nette,  the  sweet  pea,  and  the  poppy,  take  in  just  enough 
food  to  supply  their  daily  wants  and  to  make  the 
seeds  we  shall  speak  of  presently.  Then,  as  soon  as 
their  seeds  are  ripe  their  roots  begin  to  shrivel,  and 


1 62  THE  FAIRY-LAND  OF  SCIENCE. 

water  is  no  longer  carried  up.  The  green  cells  can  no 
longer  get  food  to  digest,  and  they  themselves  are 
broken  up  by  the  sunbeams  and  turn  yellow,  and  the 
plant  dies. 

But  many  plants  are  more  industrious  than  the 
stock  and  mignonette,  and  lay  by  store  for  another 
year,  and  our  primrose  is  one  of  these.  Look  at  this 
thick  solid  mass  below  the  primrose  leaves,  out  of 
which  the  roots  spring.*  This  is  really  the  stem  of 
the  primrose  hidden  underground,  and  all  the  starch, 
albuminoids,  &c.,  which  the  plant  can  spare  as  it 
grows,  are  sent  down  into  this  underground  stem  and 
stored  up  there,  to  lie  quietly  in  the  ground  through 
the  long  winter,  and  then  when  the  warm  spring  comes 
this  stem  begins  to  send  out  leaves  for  a  new  plant. 

We  have  now  seen  how  a  plant  springs  up,  feeds 
itself,  grows,  stores  up  food,  withers,  and  dies ;  but  we 
have  said  nothing  yet  about  its  beautiful  flowers  or 
how  it  forms  its  seeds.  If  we  look  down  close  to  the 
bottom  of  the  leaves  in  a  primrose  root  in  spring-time, 
we  shall  always  find  three  or  four  little  green  buds 
nestling  in  among  the  leaves,  and  day  by  day  we  may 
see  the  stalk  of  these  buds  lengthening  till  they  reach 
up  into  the  open  sunshine,  and  then  the  flower  opens 
and  shows  its  beautiful  pale-yellow  crown. 

We  all  know  that  seeds  are  formed  in  the  flower, 
and  that  the  seeds  are  necessary  to  grow  into  new 
plants.  But  do  we  know  the  history  of  how  they 
are  formed,  or  what  is  the  use  of  the  different  parts 
of  the  bud  t    Let  us  examine  them  all,  and  then  I 

•  See  the  plant  in  the  foreground  of  the  heading  of  the  lecture. 


THE  LIFE  OF  A  PRIMROSE. 


think  you  will  agree  with  me  that  this  is  not  the  least 
wonderful  part  of  the  plant. 

Remember  that  the  seed  is  the  one  important  thing, 
and  then  notice  how  the  flower  protects  it.  First, 
look  at  the  outside  green  covering,  which  we  call  the 
calyx.  See  how  closely  it  fits  in  the  bud,  so  that  no 
insects  can  creep  in  to  gnaw  the  flower,  nor  any  harm 
come  to  it  from  cold  or  blight.  Then,  when  the  calyx 
opens,  notice  that  the  yellow  leaves  which  form  the 
crown  or  corolla,  are  each  alternate  with  one  of  the 
calyx  leaves,  so  that  anything  which  got  past  the  first 
covering  would  be  stopped  by  the  second.  Lastly, 
when  the  delicate  corolla  has  opened  out,  look  at 
those  curious  yellow  bags  just  at  the  top  of  the  tube 
{b^2^  Fig.  43).  What  is  their  use  ? 


Fig.  43. 


The  two  forms  of  the  Primrose-flower. 


fz,  Stigma  or  sticky  head  of  the  seed-vessel,  Anthers  of  the 
^tannens.  Corolla  or  crown  of  the  flower,  Calyx  or  outer  covering, 
r^',  Seed-vessel.  A,  Enlarged  pistil,  with  pollen-grain  resting  on  the 
stigma  and  growing  down  to  the  ovule,  Ovules. 

But  I  fancy  I  see  two  or  three  little  questioning 
faces  which  seem  to  say,  "  I  see  no  yellow  bags  at 


I64  iHE  FAIRY-LAND  OF  SCIENCE. 


the  top  of  the  tube."  Well,  I  cannot  tell  whether 
you  can  or  not  in  the  specimen  you  have  in  your 
hand  ;  for  one  of  the  most  curious  things  about  prim- 
rose flowers  is,  that  some  of  them  have  these  yellow 
bags  at  the  top  of  the  tube  and  some  of  them  hidden 
down  right  in  the  middle.  But  this  I  can  tell  you  : 
those  of  you  who  have  got  no  yellow  bags  at  the  top 
will  have  a  round  knob  there  (l  ^,  Fig.  43),  and  will 
find  the  yellow  bags  {U)  buried  in  the  tube.  Those, 
on  the  other  hand,  who  have  the  yellow  bags  (2  by 
Fig.  43)  at  the  top  will  find  the  knob  {a)  half-way 
down  the  tube. 

Now  for  the  use  of  these  yellow  bags,  which  are 
called  the  anthers  of  the  stamens,  the  stalk  on  which 
they  grow  being  called  the  filament  or  thread.  If 
you  can  manage  to  split  them  open  you  will  find  that 
they  have  a  yellow  powder  in  them,  called  pollen,  the 
same  as  the  powder  which  sticks  to  your  nose  when 
you  put  it  into  a  lily;  and  if  you  look  with  a  magni- 
fying glass  at  the  little  green  knob  in  the  centre  of 
the  flower  you  will  pi  obably  see  some  of  this  yellow 
dust  sticking  on  it  (A,  Fig.  43).    We  will  leave  it 
there  for  a  time,  and  examine  the  body  called  the 
pistil,  to  which  the  knob  belongs.    Pull  off  the  yellow 
corolla  (which  will  come  off  quite  easily),  and  turn 
back  the  green  leaves.    \'gu  will  then  see  that  the 
knob  stands  on  the  top  of  a  column,  and  at  the 
bottom  of  this  column  there  is  a  round  ball  {sv^, 
which  is  a  vessel  for  holding  the  seeds.     In  this 
diagram  (A,  Fig.  43)  I  have  drawn  the  whole  of  this 
curious  ball  and  column  as  if  cut  in  half,  so  that  we 
may  see  what  is  in  it.    In  the  middle  of  the  ball,  in  a 


THE  LIFE  OF  A  PRIMROSE. 


I6S 


cluster,  there  are  a  number  of  round  transparent  little 
bodies,  looking  something  like  round  green  orange- 
cells  full  of  juice.  They  are  really  cells  full  of  proto- 
plasm, with  one  little  dark  spot  in  each  of  them,  which 
by-and-by  is  to  make  our  little  plantlet  that  we  found 
in  the  seed. 

"  These,  then,  are  seeds,"  you  will  say.  Not  yet  ; 
they  are  only  oviUes,  or  little  bodies  which  may 
become  seeds.  If  they  were  left  as  they  are  they 
would  all  wither  and  die.  But  those  little  yellow 
grains  of  pollen,  which  we  saw  sticking  to  the  knob  at 
the  top,  are  coming  down  to  help  them  As  soon  as 
these  yellow  grains  touch  the  sticky  knob  or  stigma, 
as  it  is  called,  they  throw  out  tubes,  which  grow 
down  the  column  until  they  reach  the  ovules.  In 
each  one  of  these  they  find  a  tiny  hole,  and  into 
this  they  creep,  and  then  they  pour  into  the  ovule  all 
the  protoplasm  from  the  pollen-grain  which  is  sticking 
above,  and  this  enables  it  to  grow  into  a  real  seed, 
with  a  tiny  plantlet  inside. 

This  is  how  the  plant  forms  its  seed  to  bring  up 
new  little  ones  next  year,  while  the  leaves  and  the 
roots  are  at  work  preparing  the  necessary  food. 
Think  sometimes  when  you  walk  in  the  woods,  how 
hard  at  work  the  little  plants  and  big  trees  are,  all 
around  you.  You  breathe  in  the  nice  fresh  oxygen 
they  have  been  throwing  out,  and  little  think  that  it 
13  they  who  are  making  the  country  so  fresh  and 
pleasant,  and  that  while  they  look  as  if  they  were 
doing  nothing  but  enjoying  the  bright  sunshine,  they 
are  really  fulfilling  their  part  in  the  world  by  the  help 
of  this  sun^^hine  ;  earning  their  food  from  the  ground  ; 


1 66  THE  FAIRY-LAND  OF  SCIENCE. 


working  it  up  ;  turning  their  leaves  where  they  can 
best  get  light  (and  in  this  it  is  chiefly  the  violet  sun- 
waves  that  help  them),  growing,  even  at  night,  by 
making  new  cells  out  of  the  food  they  have  taken  in 
the  day  ;  storing  up  for  the  winter  ;  putting  out  theif 
flowers  and  making  their  seeds,  and  all  the  while 
smiling  so  pleasantly  in  quiet  nooks  and  sunny  dells 
that  it  makes  us  glad  to  see  them. 

But  why  should  the  primroses  have  such  golden 
crowns  ?  plain  green  ones  would  protect  the  seed  quite 
as  well.  Ah  !  now  we  come  to  a  secret  well  worth 
knowing.  Look  at  the  two  primrose  flowers,  I  and  2, 
Fig.  43,  p.  163,  and  tell  me  how  you  think  the  dust  gets 
on  to  the  top  of  the  sticky  knob  or  stigma.  No.  2 
seems  easy  enough  to  explain,  for  it  looks  as  if  the 
pollen  could  fall  dow^n  easily  from  the  stamens  on  to 
the  knob,  but  it  cannot  fall  icp,  as  it  would  have  to  do 
in  No.  I.  Now  the  curious  truth  is,  as  Mr.  Darwin 
has  shown,  that  neither  of  these  flowers  can  get  the 
dust  easily  for  themselves,  but  of  the  two  No.  I  has 
the  least  difficulty. 

Look  at  a  withered  primrose,  and  see  how  it  holds 
its  head  down,  and  after  a  little  while  the  yellow 
crown  falls  off".  It  is  just  about  as  it  is  falling  that 
the  anthers  or  bags  of  the  stamens  burst  open,  and 
then,  in  No.  I  (Fig.  44),  they  are  dragged  over  the 
knob  and  some  of  the  grains  stick  there.  But  in  the 
other  form  of  primrose,  No.  2,  when  the  flower  falls  off, 
the  stamens  do  not  come  near  the  knob,  so  it  has  no 
chance  of  getting  any  pollen ;  and  while  the  primrose 
is  upright  the  tube  is  so  narrow  that  the  dust  does  not 
easily  fall.    But,  as  I  have  said,  neither  kind  gets  it 


THE  LIFE  OF  A  PRIMROSE, 


167 


j/ery  easily,  nor  is  it  good  for  them  if  they  do.  The 
seeds  are  much  stronger  and  better  if  tlie  dust  or 
pollen  of  one  flower  is  carried  away  and  left  on  the 


Fig.  44. 


Corolla  of  Primrose  tailing  otf, 

I,  Primrose  with  long  pistil,  and  stamens  in  the  tube,  same  as  I  of 
Fig.  43.  2,  Primrose  with  short  pistil,  and  stamens  at  mouth  of  tube,  2, 
Fig.  43- 

knob  or  stigma  of  another  flower :  and  the  only  way 
this  can  be  done  is  by  insects  flying  from  one  flower 
to  another  and  carrying  the  dust  on  their  legs  and 
bodies. 

If  you  suck  the  end  of  the  tube  of  the  primrose 
flower  you  will  find  it  tastes  sweet,  because  a  drop  of 
honey  has  been  lying  there.  When  the  insects  go  in 
to  get  this  honey,  they  brush  themselves  against  the 
yellow  dust-bags,  and  some  of  the  dust  sticks  to  them, 
and  then  when  they  go  to  the  next  flower  they  rub  it 
08"  on  to  its  sticky  knob. 

Look  at  No.  I  and  No.  2  (Fig.  43)  and  you  will  sec 
at  once  that  if  an  insect  goes  into  No.  I  and  the  pollen 
sticks  to  him,  when  he  goes  into  No.  2  just  that  part 
of  his  body  on  which  the  pollen  is  will  touch  th<? 


l68  THE  FAIRY-LAND  OF  SCIENCE, 


knob  ;  and  so  the  flowers  become  what  we  call 
"crossed,"  that  is,  the  pollen-dust  of  the  one  feeds 
the  ovule  of  the  other.  And  just  tlie  same  thing  will 
happen  if  he  flies  from  No.  2  to  No.  i.  There  the 
dust  will  be  just  in  the  position  to  touch  the  knob 
which  sticks  out  of  the  flower. 

Therefore,  we  can  see  clearly  that  it  is  good  for  the 
primrose  that  bees  and  other  insects  should  come  to 
it,  and  anything  it  can  do  to  entice  them  will  be 
useful.  Now,  do  you  not  think  that  when  an  insect 
once  knew  that  the  pale-yellow  crown  showed  where 
honey  was  to  be  found,  he  would  soon  spy  these 
crowns  out  as  he  flew  along  t  or  if  they  were  behind 
a  hedge,  and  he  could  not  see  them,  would  not  the 
sweet  scent  tell  him  where  to  come  and  look  tor 
them  ?  And  so  we  see  that  the  pretty  sweet-scented 
corolla  is  not  only  delightful  for  us  to  look  at  and 
to  smell,  but  it  is  really  very  useful  in  helping  the 
primrose  to  make  strong  healthy  seeds  out  of  which 
the  young  plants  are  to  grow  next  year. 

And  now  let  us  see  what  we  have  learnt.  We  began 
with  a  tiny  seed,  though  we  did  not  then  know  how 
this  seed  had  been  made.  We  saw  the  plantlet  buried 
in  it,  and  learnt  how  it  fed  at  first  on  prepared  food, 
but  soon  began  to  make  living  matter  for  itself  out  of 
gases  taken  from  the  water  and  the  air.  How  inge- 
niously it  pumped  up  the  water  through  the  cells  to 
its  stomach — the  leaves !  And  how  marvellously  the 
sun-waves  entering  there  formed  the  little  green 
granules,  and  then  helped  them  to  make  food  and 
livirg  protoplasm !    At  this  point  we  might  have 


THE  LIFE  OF  A  PRIMROSE. 


169 


gone  further,  and  studied  how  the  fibres  and  all  the 
different  vessels  of  the  plant  are  formed,  and  a  won- 
drous history  it  would  have  been.  But  it  was  too 
long  for  one  hour's  lecture,  and  you  must  read  it  for 
yourselves  in  books  on  botany.  We  had  to  pass  on 
to  the  flower,  and  learn  the  use  of  the  covering  leaves, 
the  gaily  coloured  crown  attracting  the  insects,  the 
dust-bags  holding  the  pollen,  the  little  ovules  each 
with  the  germ  of  a  new  plantlet,  lying  hidden  in  the 
seed-vessel,  waiting  for  the  pollen-grains  to  grow 
down  to  them.  Lastly,  when  the  pollen  crept  in  at 
the  tiny  opening  we  learnt  that  the  ovule  had  now 
all  it  wanted  to  grow  into  a  perfect  seed 

And  so  we  came  back  to  a  primrose  seed,  the  point 
from  which  we  started  ;  and  we  have  a  history  of  our 
primrose  from  its  birth  to  the  day  when  its  leaves 
and  flowers  wither  away  and  it  dies  down  for  the 
winter. 

But  what  fairies  are  they  which  have  been  at  work 
here  ?  First,  the  busy  little  fairy  Life  in  the  active 
protoplasm  ;  and  secondly,  the  sun-waves.  We  have 
seen  that  it  was  by  the  help  of  the  sunbeams  that  the 
green  granules  were  made,  and  the  water,  carbonic 
acid,  and  nitrogen  worked  up  into  the  living  plant. 
And  in  doing  this  work  the  sun-waves  were  caught 
and  their  strength  used  up,  so  that  they  could  no 
longer  quiver  back  into  space.  But  are  they  gone  fo¥» 
ever  }  So  loner  as  the  leaves  or  the  stem  or  the  root 
of  the  plant  remain  they  are  gone,  but  when  those  are 
destroyed  we  can  get  them  back  again.  Take  a 
handful  of  dry  withered  plants  and  light  them  with  a 
match,  then  as  the  leaves  burn  and  are  turned  Lack 


I/O  THE  FAIRY-LAND  OF  SCIENCE. 


again  to  carbonic  acid,  nitrogen,  and  water,  our  sun- 
beams come  back  again  in  the  flame  and  heat. 

And  the  life  of  tlie  plant  ?  What  is  it,  and  why  is 
this  protoplasm  always  active  and  busy  ?  I  caiinr  t 
tell  you.  Study  as  we  may,  the  life  of  the  tiny  plar  i 
is  as  much  a  mystery  as  your  life  and  mine.  It  canity 
like  all  things,  from  the  bosom  of  the  Great  Father, 
but  we  cannot  tell  how  it  came  nor  what  it  is.  We  can 
see  the  active  grains  moving  under  the  microscope, 
but  we  cannot  see  the  power  that  moves  them.  We 
only  know  it  is  a  power  given  to  the  plant,  as  to  you 
and  to  me,  to  enable  it  to  live  its  life,  and  to  do  its 
useful  work  in  the  world. 


A  PTECE  OF  COAL. 


171 


LECTURE  VIII. 


THE  HISTORY  OF  A  PIECE  OF  CO/ 


HAVE  here  a  piece  of  coal 
(Fig.  45),  which,  though 
it  has  been  cut  with  some 
care  so  as  to  have  a  smooth  face,  is  really  in  no  other 
way  different  from  any  ordinary  lump  whicli  you  can 


1 7  2  THE  FA  IR  Y'LA  ND  OF  SCIENCE 


pick  for  yourself  out  of  the  coal-scuttle.  Our  work 
to-day  is  to  relate  the  history  of  this  black  lump  ;  ta 
learn  what  it  is,  what  it  has  been,  and  what  it  will  be. 

Fig.  45- 


Piece  of  coal, 
a,  Smooth  face,  showing  laminae  or  thin  layers. 


It  looks  uninteresting  enough  at  first  sight,  and  yel 
if  we  examine  it  closely  we  shall  find  some  questions 
to  ask  even  about  its  appearance.  Look  at  the 
smooth  face  of  this  specimen  and  see  if  you  can 
explain  those  fine  lines  which  run  across  so  close 
together  as  to  look  like  the  edges  of  the  leaves  of  a 
book.  Try  to  break  a  piece  of  coal,  and  you  will  find 
that  it  will  split  much  more  easily  along  those  lines 
than  across  the  other  way  of  the  lump  ;  and  if  you  wish 
to  light  a  fire  quickly  you  should  always  put  this 
lined  face  downwards  so  that  the  heat  can  force  its 
way  up  through  these  cracks  and  gradually  split  up 
the  block.  Then  again  if  you  break  the  coal  carefully 
along  one  of  these  lines  you  will  find  a  fine  film  of 
charcoal  lying  in  the  crack,  and  you  will  begin  to  sus- 
pect that  this  black  coal  must  have  been  built  up  in 


A  PIECE  OF  COAL, 


very  thin  layers,  with  a  kind  of  black  dust  between 
them. 

The  next  thing  you  will  call  to  mind  is  that  this 
coal  burns  and  gives  flame  and  heat,  and  that  this 
means  that  in  some  way  sunbeams  are  imprisoned  in 
it ;  lastly,  this  will  lead  you  to  think  of  plants,  and 
how  they  work  up  the  strength  of  the  sunbeams  into 
their  leaves,  and  hide  black  carbon  in  even  the 
purest  and  whitest  substance  they  contain. 

Is  coal  made  of  burnt  plants,  then  }  Not  burnt  ones, 
for  if  so  it  would  not  burn  again  ;  but  you  may  have 
read  how  the  makers  of  charcoal  take  wood  and  bake 
it  without  letting  it  burn,  and  then  it  turns  black 
and  will  afterwards  make  a  very  good  fire ;  and 
so  you  will  see  that  it  is  probable  that  our  pieoe  of 
coal  is  made  of  plants  which  have  been  baked  and 
altered,  but  which  have  still  much  sunbeam  strength 
bottled  up  in  them,  which  can  be  set  free  as  they 
burn. 

If  you  will  take  an  imaginary  journey  with  me  to  a 
coal-pit  near  Newcastle,  which  I  visited  many  years 
ago,  you  will  see  that  we  have  very  good  evidence  that 
coal  is  made  of  plants,  for  in  all  coal-mines  we  find 
remains  of  them  at  every  step  we  take. 

Let  us  imagine  that  we  have  put  on  old  clothes  which 
will  not  spoil,  and  have  stepped  into  the  iron  basket 
(see  Fig.  46)  called  by  the  miners  a  cage^  and  are  being 
let  down  the  shaft  to  the  gallery  where  the  miners  are 
at  work.  Most  of  them  will  probably  be  in  the  gal- 
lery ^,  because  a  great  deal  of  the  coal  in  a  has  been 
already  taken  out.  But  we  will  stop  in  a  because 
there  we  can  see  a  great  deal  of  the  roof  and  the 


'74 


THE  FAIRY-LAND  OF  SCIENCE. 


floor.  When  we  land  on  the  floor  of  the  gallery  we 
shall  find  ourselves  in  a  kind  of  tunnel  with  railway 
lines  laid  along  it  and  trucks  laden  with  coal  coming 

Fig.  46. 


stone 


noof 

Coftl 

Floor 

Sand 
stone 

Roof 
.  Coal 
Floor 

Sand 
stone 


Imaginary  section  of  a  coal-mine. 

towards  the  cage  to  be  drawn  up,  while  empty  ones 
are  running  back  to  be  loaded  where  the  miners  are 
at  work.  Taking  lamps  in  our  hands  and  keeping 
out  of  the  way  of  the  trucks,  we  will  first  throw  the 
light  on  the  roof,  which  is  made  of  shale  or  hardened 
clay.  We  shall  not  have  gone  many  yards  before 
we  see  impressions  of  plants  in  the  shale,  like  those  in 
this  specimen  (Fig.  47),  which  was  taken  out  of  a 
coal-mine  at  Neath  in  Glamorganshire,  a  few  days 
ago,  and  sent  up  for  this  lecture.  You  will  recognize 
at  once  the  marks  of  ferns  (a),  for  they  look  like  those 
you  gather  in  the  hedges  of  an  ordinary  country  lane, 
and  that  long  striped  branch  {U)  does  not  look  unlike 
a  reed,  and  indeed  it  is  something  of  this  kind,  as  we 


A  PIECE  OF  COAL, 


175 


shall  see  by-and-by.  You  will  find  plenty  of  these 
impressions  of  plants  as  you  go  along  the  gallery  and 
look  up  at  the  roof,  and  with  them  there  will  be  others 

Fig.  47. 


A  piece  of  shale  with  impressions  of  ferns  and  Calamite  stems. 

with  spotted  stems,  or  with  stems  having  a  curious 
diamond  pattern   upon   them,  and   many  ferns  of 
various  kinds. 
Next  look  down  at  your  feet  and  examine  the  floor. 


Fig,  48. 


Gtigmaria-^root  or  underground  stem  of  Sigillaria. 

You  will  not  have  to  search  long  before  you  will 
almost  certainly  find  a  piece  of  stone  like  that  repre- 
sented in  Fig.  48,  which  has  also  come  from  Neath 


1/6  THE  FAIRY-LAND  OF  SCIENCE. 


Colliery.*  This  fossil,  which  is  the  cast  of  a  piece  of  a 
plant,  puzzled  those  who  found  it  for  a  very  long  time. 
At  last,  however,  Mr.  Binney  found  the  specimen 
growing  to  the  bottom  of  the  trunk  of  one  of  the  fossil 
trees  with  spotted  stems,  called  Sigillaria ;  and  so 
proved  that  this  curious  pitted  stone  is  a  piece  of 
fossil  root,  or  rather  underground  stem,  like  that 
which  we  found  in  the  primrose,  and  that  the  little 
pits  or  dents  in  it  are  scars  where  the  rootlets  once 
were  given  off. 

Whole  masses  of  these  root-stems,  with  ribbon-like 
roots  lying  scattered  near  them,  are  found  buried  in 
the  layer  of  clay  called  the  underclay  which  makes 
the  floor  of  the  coal,  and  they  prove  to  us  that  this 
underclay  must  have  been  once  the  ground  in  which 
the  roots  of  the  coal-plants  grew.  You  will  feel  still 
more  sure  of  this  when  you  find  that  there  is  not  only 
one  straight  gallery  of  coal,  but  that  galleries  branch 
out  right  and  left,  and  that  everywhere  you  find  the 
coal  lying  like  a  sandwich  between  the  floor  and  the 
roof,  showing  that  quite  a  large  piece  of  country  must 
be  covered  by  these  remains  of  plants  all  rooted  in  the 
underclay. 

But  how  about  the  coal  itself  }  It  seems  likely, 
when  we  find  roots  below  and  leaves  and  stems  above, 
that  the  middle  is  made  of  plants,  but  can  we  prove 
it  }  We  shall  see  presently  that  it  has  been  so 
crushed  and  altered  by  being  buried  deep  in  the 
ground  that  the  traces  of  leaves  have  almost  been 

♦  1  am  much  indebted  to  Mr.  John  Willictms,  of  Neath,  for  pro- 
curing these  lossils  for  me  ;  and  also  to  Professor  Judd  for  lending  me 
gome  for  an  eailier  lecture. 


A  PIECE  OF  COAL. 


\77 


destroyed,  though  people  who  are  used  to  examhiing 
with  the  microscope,  can  see  the  crushed  remains  oi 
plants  in  thin  slices  of  coal. 

But  fortunately  for  us,  perfect  pieces  of  plants  have 
been  preserved  even  in  the  coal-bed  itself.  Do  you  re- 
member our  learning  in  Lecture  IV.  that  water  with 
lime  in  it  petrifies  things,  that  is,  leaves  carbonate  of 
lime  to  fill  up  grain  by  grain  the  fibres  of  an  animal 
or  plant  as  the  living  matter  decays,  and  so  keeps  an 
exact  representation  of  the  object  1 

Now,  it  so  happens  that  in  a  coal-bed  at  South 
Ouram,  near  Halifax,  as  well  as  in  some  other  places, 
carbonate  of  lime  trickled  in  before  the  plants  were 
turned  into  coal,  and  made  some  round  nodules  in  the 
plant-bed,  which  look  like  cannon-balls.  Afterwards, 
when  all  the  rest  of  the  bed  was  turned  into  coal,  these 
round  balls  remained  crystallized,  and  by  cutting  thin 
transparent  slices  across  the  nodule  we  can  distinctly 
see  the  leaves  and  stems  and  curious  little  round 
bodies  which  make  up  the  coal.  Several  such  sections 
may  be  seen  at  the  British  Museum,  and  when  we 
compare  these  fragments  of  plants  with  those  which 
we  find  above  and  below  the  coal-bed,  we  find  that 
they  agree,  thus  proving  that  coal  is  made  of  plants, 
and  of  those  plants  whose  roots  grew  in  the  clay  floor, 
while  their  heads  reached  up  far  above  where  the  root 
now  is. 

The  next  question  is,  what  kind  of  plants  were 
these  Have  we  anything  like  them  living  in  the 
world  now  }  You  might  perhaps  think  that  it  would 
be  impossible  to  decide  this  question  from  mere 
petrified  pieces  of  plants.    But  many  men  have  spent 


178  THE  FAIRY-LAND  OF  SCIENCE. 


their  whole  Hves  in  deciphering  all  the  fragments  that 
could  be  found,  and  though  the  section  given  in 
Fig.  49  may  look  to  you  quite  incomprehensible,  yet 


Fig.  49. 


Contents  of  a  coal-ball.  (Carruthers.) 


5",  Stem  of  Sigillaria  cut  across.  Z,  Stem  of  Lepidodendron  cut  across. 
Z',  Stem  of  Lepidodendron  cut  lengthways.  /,  cone  of  Lepidodendron 
(Lepidostrobus)  cut  across.  Stem  of  Calamite  cut  across,  Fruit 
of  Calamite  lengthways  and  across,  Stem  of  a  fern  with  fragments 
of  fern-leaves  scattered  round  it.  The  small  round  dots  scattered  here 
and  there  are  the  larger  spores  which  have  fallen  out  of  the  fruit-cones. 

a  botanist  can  read  it  as  we  read  a  book.  For  ex- 
ample, at  S  and  L,  where  stems  are  cut  across,  he  can 

•  I  am  much  indebted  to  Mr.  Carruthers,  of  the  British  Museum,  for 
allowing  me  to  copy  this  figure  from  his  original  diagram  of  a  coal-ball, 
and  also  for  jiving  me  much  valuable  assistance. 


A  PIECE  OF  COAL. 


179 


learn  exactly  how  they  were  built  up  inside,  and  com- 
pare theni  with  the  stems  of  living  plants,  while  the 
fruits  cc  and  the  little  round  spores  lying  near  them, 
tell  him  their  history  as  well  as  if  he  had  gathered  them 
from  the  tree.  In  this  way  we  have  learnt  to  know 
very  fairly  what  the  plants  of  the  coal  were  like,  and 
you  will  be  surprised  when  I  tell  you  that  the  huge 
trees  of  the  coal-forests,  of  which  we  sometimes  find 
trunks  in  the  coal-mines  from  ten  to  fifty  feet  long,  are 
only  represented  on  the 
earth  now  by  small  insig- 
nificant  plants,  scarcely 
ever  more  than  two  feet, 
and  often  not  many 
inches  high. 

Have  you  ever  seen 
the  little  club-  moss  or  Ly- 
copodium  which  grows 
all  over  England,  but 
chiefly  in  the  north,  on 
heaths  and  mountains } 
At  the  end  of  each  of 
its  branches  it  bears  a 
cone  made  of  scaly 
leaves  ;  and  fixed  to  the 
inside  of  each  of  these 
leaves  is  a  case  called 
a  sporangium,  full  of  little  spores  or  moss-seeds,  as 
we  may  call  them,  though  they  are  not  exactly  like  true 
seeds.  In  one  of  these  club-mosses  called  Selagmella, 
the  cases  B  near  the  bottom  of  the  cone  contain  large 
spores       while  those  near  the  top,  A,  contain  a 


Selaginella  selaginoides. 
Species  of  club- moss  bearing  two 
kinds  of  spores. 


l8o  THE  FAIRY' LAND  OF  SCIENCE. 


powdery  dust  a.  These  spores  are  full  of  resin,  and 
they  are  collected  on  the  Continent  for  making  arti- 
ficial lightning  in  the  theatres,  because  they  flare  when 
lighted. 

Now  this  little  Selaginella  is  of  all  living  plants  the 
one  most  like  some  of  the  gigantic  trees  of  the  coal- 
forests.  If  you  look  at  this  picture  of  a  coal-forest 
(Fig.  si),  you  will  find  it  difficult  perhaps  to  believe 
that  those  great  trees,  with  diamond  markings  all  up 
the  trunk,  hanging  over  from  the  right  to  the  left  of 
the  picture,  and  covering  all  the  top  with  their  boughs, 
could  be  in  any  way  relations  of  the  little  Selaginella ; 
yet  we  find  branches  of  them  in  the  beds  above  the 
coal,  bearing  cones  larger  but  just  like  Selaginella 
cones ;  and  what  is  most  curious,  the  spores  in  these 
cones  are  of  exactly  the  same  kind  and  not  any  larger 
than  those  of  the  club-moss. 

These  trees  are  called  by  botanists  Lepidodendrons, 
or  scaly  trees ;  there  are  numbers  of  them  in  all  coal- 
mines, and  one  trunk  has  been  found  49  feet  long. 
Their  branches  were  divided  in  a  curious  forked 
manner  and  bore  cones  at  the  ends.  The  spores 
which  fell  from  these  cones  are  found  flattened  in  the 
coal,  and  they  may  be  seen  scattered  about  in  the 
coal-ball  (Fig.  49). 

Another  famous  tree  which  grew  in  the  coal-forests 
was  the  one  whose  roots  we  found  in  the  floor  or 
undei'clay  of  the  coal.  It  has  been  called  Sigillaria, 
because  it  has  marks  like  seals  {sigilhtm,  a  seal)  all 
up  the  trunk,  due  to  the  scars  left  by  the  leaves  when 
they  fell  from  the  tree.  You  will  see  the  Sigillarias 
on  the  left-hand  side  of  the  coal-forest  picture,  having 
those  curious  tufts  of  leaves  springing  out  of  them  at 


^  Ig-  51. 


I 


A  Forest  of  the  Coal  Period. 

To  face  p.  180. 


A  PIECE  OF  COAL. 


the  top.  Their  stems  make  up  a  great  deal  of  the  coal, 
and  the  bark  of  their  trunks  is  often  found  in  the  clays 
above,  squeezed  flat  in  lengths  of  30,  60,  or  70  feet. 
Sometimes,  instead  of  being  flat  the  bark  is  still  in  the 
shape  of  a  trunk,  and  the  interior  is  filled  with  sand ; 
and  then  the  trunk  is  very  heavy,  and  if  the  miners  do 
not  prop  the  roof  up  well  it  falls  down  and  kills  those 
beneath  it.  Stigmaria  (Fig.  48,  page  175)  is  the  root  of 
the  Sigillaria,  and  is  found  in  the  clays  below  the  coal. 
Botanists  are  not  yet  quite  certain  about  the  seed- 
cases  of  this  tree,  but 
Mr.  Carruthers  believes 
that  they  grew  inside 
the  base  of  the  leaves,  as 
they  do  in  the  quillwort, 
a  small  plant  which 
grows  at  the  bottom  of 
our  mountain  lakes. 

But  what  is  that 
curious  reed-like  stem 
we  found  in  the  piece 
of  shale  (see  Fig.  47)  ? 
That  stem  is  very  im- 
portant, for  it  belonged 
to  a  plant  called  a  Cala- 
mitCy  which,  as  we  shall 
see  presently,  helped  to 
sift  the  earth  away  from 
the  coal  and  keep  it 

.       -  Equisetum  or  horsetail, 

pure.    This  plant  was 

a  near  relation  of  the  "horsetail,"  or  Equisetum,  which 
grows  in  our  marshes  ;  only,  just  as  in  the  case  of  the 
other  trees,  it  was  enormously  larger,  being  often 
13 


I82 


THE  FAIRY-LAND  OF  SCIENCE. 


20  feet  high,  whereas  the  little  Equisetum,  Fig.  52,  is 
seldom  more  than  a  foot,  and  never  more  than  4  feet 
high  in  England,  though  in  tropical  South  America 
they  are  much  higher.  Still,  if  you  have  ever  gathered 
horsetails,''  you  will  see  at  once  that  those  trees  in 
the  foreground  of  the  picture  (Fig.  51),  with  leaves 
arranged  in  stars  round  the  branches,  are  only  larger 
copies  of  the  little  marsh-plants  ;  and  the  seed-vessels 
of  the  two  plants  are  almost  exactly  the  same. 

These  great  trees,  the  Lepidodendrons,  the  Sigil- 
larias,  and  the  Calamites,  together  with  large  tree- 
ferns  and  smaller  ferns,  are  the  chief  plants  that  we 
know  of  in  the  coal-forests.  It  seems  very  sti*ange  at 
first  that  they  should  have  been  so  large  when  their 
descendants  are  now  so  small,  but  if  you  look  at  our 
chief  plants  and  trees  now,  you  will  find  that  nearly 
all  of  them  bear  flowers,  and  this  is  a  great  advantage 
to  them,  because  it  tempts  the  insects  to  bring  them 
the  pollen-dust,  as  we  saw  in  the  last  lecture. 

Now  the  Lepidodendrons  and  their  companions 
had  no  true  flowers,  but  only  these  seed-cases  which 
we  have  mentioned  ;  but  as  there  were  no  flowering 
plants  in  their  time,  and  they  had  the  ground  all  to 
themselves,  they  grew  fine  and  large.  By-and-by,  how- 
ever, when  the  flowering  plants  came  in,  these  began 
to  crowd  out  the  old  giants  of  the  coal-forests,  so 
that  they  dwindled  and  dwindled  from  century  to 
century  till  their  great-great-grandchildren,  thousands 
of  generations  after,  only  lift  up  their  tiny  heads  in 
marshes  and  on  heaths,  and  tell  us  that  they  were  big 
once  upon  a  time. 

And  indeed  they  nvuSt  have  been  magnificent  in 


A  PIECE  OF  COAL. 


i83 


those  olden  days,  when  they  grew  thick  and  tall  in 
the  lonely  marshes  where  plants  and  trees  were  the 
chief  inhabitants.  We  find  no  traces  in  the  clay-beds 
of  the  coal  to  lead  us  to  suppose  that  men  lived  in  those 
days,  nor  lions,  nor  tigers,  nor  even  birds  to  fly  among 
the  trees  ;  but  these  grand  forests  were  almost  silent, 
except  when  a  huge  animal  something  like  a  gigantic 
newt  or  frog  went  croaking  through  the  marsh,  or  a 
kind  of  grasshopper  chirruped  on  the  land.  But  these 
forms  of  life  were  few  and  far  between,  compared  to 
the  huge  trees  and  tangled  masses  of  ferns  and  reeds 
which  covered  the  whole  ground,  or  were  reflected  in 
the  bosom  of  the  large  pools  and  lakes  round  about 
which  they  grew. 

And  now,  if  you  have  some  idea  of  the  plants  and 
trees  of  the  coal,  it  is  time  to  ask  how  these  plants 
became  buried  in  the  earth  and  made  pure  coal, 
instead  of  decaying  away  and  leaving  behind  only  a 
mixture  of  earth  and  leaves  ? 

To  answer  this  question,  1  must  ask  you  to  take 
another  journey  with  me  across  the  Atlantic  to  the 
shores  of  America,  and  to  land  at  Norfolk  in  Virginia, 
because  there  we  can  see  a  state  of  things  something 
like  the  marshes  of  the  coal -forests.  All  round 
about  Norfolk  the  land  is  low,  flat,  and  marshy,  and 
to  the  south  of  the  town,  stretching  far  away  into 
North  Carolina,  is  a  large,  desolate  swamp,  no  less 
Uian  forty  miles  long  and  twenty-five  broad.  The 
whole  place  is  one  enormous  quagmire,  overgrown 
with  water-plants  and  trees.  The  soil  is  as  black  as  ink 
from  the  old,  dead  leaves,  grasses,  roots,  and  stems 


THE  FAIRY-LAND  OF  SCIENCE. 


which  lie  in  it ;  and  so  soft,  that  everything  would 
sink  into  it,  if  it  were  not  for  the  matted  roots  of  the 
mosses,  ferns,  and  other  plants  which  bind  it  together. 
You  may  dig  down  for  ten  or  fifteen  feet,  and  find 
nothing  but  peat  made  of  the  remains  of  plants 
which  have  lived  and  died  there  in  succession  for 
ages  and  ages,  while  the  black  trunks  of  the  fallen 
trees  lie  here  and  there,  gradually  being  covered  up 
by  the  dead  plants. 

The  whole  place  is  so  still,  gloomy,  and  desolate, 
that  it  goes  by  the  name  of  the  "  Great  Dismal 
Swamp,"  and  you  see  we  have  here  what  might  well 
be  the  beginning  of  a  bed  of  coal ;  for  we  know  that 
peat  ^hen  dried  becomes  firm  and  makes  an  excellent 
fire,  and  that  if  it  were  pressed  till  it  was  hard  and 
solid  it  would  not  be  unlike  coal.  If,  then,  we  can 
explain  how  this  peaty  bed  has  been  kept  pure  from 
earth,  we  shall  be  able  to  understand  how  a  coal-bed 
may  have  been  formed,  even  though  the  plants  and 
trees  which  grow  in  this  swamp  are  different  from 
those  which  grew  in  the  coal-forests. 

The  explanation  is  not  difficult ;  streams  flow 
constantly,  or  rather  ooze  into  the  Great  Dismal 
Swamp  from  the  land  that  lies  to  the  west,  but 
instead  of  bringing  mud  in  with  them  as  rivers  bring 
to  the  sea,  they  bring  only  clear,  pure  water,  because, 
as  they  filter  for  miles  through  the  dense  jungle  of 
reeds,  ferns,  and  shrubs  which  grow  round  the  marsh, 
all  the  earth  is  sifted  out  and  left  behind.  In  this 
way  the  spongy  mass  of  dead  plants  remains  free 
from  earthy  grains,  while  the  water  and  the  shade  of 
the  thick  forest  of  trees  prevent  the  leaves,  stems, 


A  PIECE  OF  COAL. 


I8S 


&c.,  from  being  decomposed  by  the  air  and  sun. 
And  so  year  after  year  as  the  plants  die  they  leave 
their  remains  for  other  plants  to  take  root  in,  and  the 
peaty  mass  grows  thicker  and  thicker,  while  tall 
cedar  trees  and  evergreens  live  and  die  in  these  vast, 
swampy  forests,  and  being  in  loose  ground  are  easily 
blown  down  by  the  wind,  and  leave  their  trunks  to  be 
covered  up  by  the  growing  moss  and  weeds. 

Now  we  know  that  there  were  plenty  of  ferns  and 
of  large  Calamites  growing  thickly  together  in  the  coal- 
forests,  for  we  find  their  remains  everywhere  in  the 
clay,  so  we  can  easily  picture  to  ourselves  how  the 
dense  jungle  formed  by  these  plants  would  fringe  the 
coal-swamp,  as  the  present  plants  do  the  Great 
Dismal  Swamp,  and  would  keep  out  all  earthy  matter, 
so  that  year  after  year  the  plants  would  die  and  form 
a  thick  bed  of  peat,  afterwards  to  become  coal. 

The  next  thing  we  have  to  account  for  is  the  bed  of 
shale  or  hardened  clay  covering  over  the  coal.  Now 
we  know  that  from  time  to  time  land  has  gone  slowly 
up  and  down  on  our  globe  so  as  in  some  places  to 
carry  the  dry  ground  under  the  sea,  and  in  others  to 
raise  the  sea-bed  above  the  water.  Let  us  suppose, 
then,  that  the  great  Dismal  Swamp  was  gradually  to 
sink  down  so  that  the  sea  washed  over  it  and  killed 
the  reeds  and  shrubs.  Then  the  streams  from  the 
west  would  not  be  sifted  any  longer  but  would  bring 
dowii  mud,  and  leave  it,  as  in  the  delta  of  the  Nile  or 
Mississippi,  to  make  a  layer  over  the  dead  plants. 
You  will  easily  understand  that  this  mud  would  have 
many  pieces  of  dead  trees  and  plants  in  it,  which  were 
stifled  and  died  as  it  covered  them  over  ;  and  thus  the 


THE  FAIRY-LAND  OF  SCIENCE, 


remains  would  be  preserved  like  those  which  we  find 
now  in  the  roof  of  the  coal-galleries. 

But  still  there  are  the  thick  sandstones  in  the  coal- 
mine to  be  explained.  How  did  they  come  there  ? 
To  explain  them,  we  must  suppose  that  the  ground 
went  on  sinking  till  the  sea  covered  the  whole  place 
where  once  the  swamp  had  been,  and  then  sea-sand 
would  be  thrown  down  over  the  clay  and  gradually 
pressed  down  by  the  weight  of  new  sand  above,  till  it 
formed  solid  sandstone  and  our  coal-bed  became 
buried  deeper  and  deeper  in  the  earth. 

At  last,  after  long  ages,  when  the  thick  mass  of 
sandstones  above  the  bed  b  (Fig.  46,  p.  174)  had  been 
laid  down,  the  sinking  must  have  stopped  and  the  land 
have  risen  a  little,  so  that  the  sea  was  driven  back; 
and  then  the  rivers  would  bring  down  earth  again  and 
make  another  clay-bed.  Then  a  new  forest  would 
spring  up,  the  ferns,  Calamites,  Lepidodendrons,  and 
Sigillarias  would  gradually  form  another  jungle,  and 
many  hundreds  of  feet  above  the  buried  coal-bed  b,  a 
second  bed  of  peat  and  vegetable  matter  would  begin 
to  accumulate  to  form  the  coal  bed  a. 

Such  is  the  history  of  how  the  coal  which  we  now 
dig  out  of  the  depths  of  the  earth  once  grew  as  beautiful 
plants  on  the  surface.  We  cannot  tell  exactly  all  the 
ground  over  which  these  forests  grew  in  England, 
because  some  of  the  coal  they  made  has  been  carried 
away  since  by  rivers  and  cut  down  by  the  waves  of 
the  sea,  but  we  ca7i  say  that  wherever  there  is  coal 
now,  there  they  must  have  been. 

Try  and  picture  to  yourselves  that  on  the  east  coast 


A  PIECE  OF  COAL. 


of  Northumberland  and  Durham,  where  all  is  now  black 
with  coal-dust,  and  grimy  with  the  smoke  of  furnaces  ; 
and  where  the  noise  of  hammers  and  steam-engines, 
and  of  carts  and  trucks  hurrying  to  and  fro,  makes  the 
country  re-echo  with  the  sound  of  labour  ;  there  ages 
ago  in  the  silent  swamp  shaded  with  monster  trees,  one 
thin  layer  of  plants  after  another  was  formed,  year  after 
year,  to  become  the  coal  we  now  value  so  much.  In 
Lancashire,  busy  Lancashire,  the  same  thing  was 
happening,  and  even  in  the  middle  of  Yorkshire  and 
Derbyshire  the  sea  must  have  come  up  and  washed  a 
silent  shore  where  a  vast  forest  spread  out  over  at  least 
700  or  800  square  miles.  In  Staffordshire,  too,  which 
is  now  almost  the  middle  of  England,  another  small 
coal-field  tells  the  same  story,  while  in  South  Wales 
the  deep  coal-mines  and  number  of  coal-seams  re- 
mind us  how  for  centuries  and  centuries  forests  must 
have  flourished  and  have  disappeared  over  and  over 
again  under  the  sand  of  the  sea. 

But  what  is  it  that  has  changed  these  beds  of  dead 
plants  into  hard,  stony  coal }  In  the  first  place  you 
must  remember  they  have  been  pressed  down  under 
an  enormous  weight  of  rocks  above  them.  We  can 
learn  something  about  this  even  from  our  common 
lead  pencils.  At  one  time  the  graphite  or  pure  carbon, 
of  which  the  blacklead  (as  we  wrongly  call  it)  of  our 
pencils  is  made,  was  dug  solid  out  of  the  earth.  But 
so  much  has  now  been  used  that  they  are  obliged 
to  collect  the  graphite  dust,  and  press  it  under  a 
heavy  weight,  and  this  makes  such  solid  pieces  that 
they  can  cut  them  into  leads  for  ordinary  cedar 
pencils. 


1 88  THE  FAIRY-LAND  OF  SCIENCE. 


Now  the  pressure  which  we  can  exert  by  machinery 
is  absolutely  nothing  compared  to  the  weight  of  all 
those  hundreds  of  feet  of  solid  rock  which  lie  over  the 
coal-beds,  and  which  has  pressed  them  down  for  thou- 
sands and  perhaps  millions  of  years ;  and  besides  this, 
we  know  that  parts  of  the  inside  of  the  earth  are  very 
hot,  and  many  of  the  rocks  in  which  coal  is  found  are 
altered  by  heat.    So  we  can  picture  to  ourselves  that 
the  coal  was  not  only  squeezed  into  a  solid  mass, 
but  often  much  of  the  oil  and  gas  which  were  in  the 
leaves  of  the  plants  was  driven  out  by  heat,  and  the 
whole  baked,  as  it  were,  into  one  substance.    The  dif- 
ference between  coal  which  flames  and  coal  which 
burns  only  with  a  red  heat,  is  chiefly  that  one  has  been 
baked  and  crushed  more  than  the  other.    Coal  which 
flames  has  still  got  in  it  the  tar  and  the  gas  and  the 
oils  which  the  plant  stored  up  in  its  leaves,  and  these 
when  they  escape  again  give  back  the  sunbeams  in  a 
bright  flame.    The  hard  stone  coal,  on  the  contrary, 
has  lost  a  great  part  of  these  oils,  and  only  carbon 
remains,  which  seizes  hold  of  the  oxygen  of  the  air 
and  burns  without  flame.    Coke  is  pure  carbon,  which 
we  make  artificially  by  driving  out  the  oils  and  gases 
from  coal,  and  the  gas  we  burn  is  part  of  what  is 
driven  out. 

We  can  easily  make  coal-gas  here  in  this  room.  I 
have  brought  a  tobacco-pipe,  the  bowl  of  which  is 
filled  with  a  little  powdered  coal,  and  the  broad  end 
cemented  up  with  Stourbridge  clay.  When  we  place 
this  bowl  over  a  spirit-lamp  and  make  it  very  hot,  the 
gas  is  driven  out  at  the  narrow  end  of  the  pipe  and 
lights  easily  (see  Fig.  53).  This  is  the  way  all  our  gas 


A  PIECE  OF  COAL. 


189 


is  made,  only  that  furnaces  are  used  to  bake  the  coal 
in,  and  the  gas  is  passed  into  large  reservoirs  till  it  is 
wanted  for  use. 


Fig.  53- 


You  will  find  it  difficult  at  first  to  understand  how 
coal  can  be  so  full  of  oil  and  tar  and  gases,  until  you 
have  tried  to  think  over  how  much  of  all  these  there  is 
in  plants,  and  especially  in  seeds — -think  of  the  oils  oi 
almonds,  of  lavender,  of  cloves,  and  of  caraways  ;  and 
the  oils  of  turpentine  which  we  get  from  the  pines, 
and  out  of  which  tar  is  made.  When  you  remember 
these  and  many  more,  and  also  how  the  seeds  of  the 
club-moss  now  are  largely  charged  wdth  oil,  you  will 
easily  imagine  that  the  large  masses  of  coal-plants 
which  have  been  pressed  together  and  broken  and 
crushed,  would  give  out  a  great  deal  of  oil  which, 
when  made  very  hot,  rises  up  as  gas.  You  may  often 
yourself  see  tar  oozing  out  of  the  lumps  of  coal  in  a 
fire,  and  making  little  black  bubbles  which  burst  and 
burn.  It  is  from  this  tar  that  James  Young  first  made 
the  paraffin  oil  we  burn  in  our  lamps,  and  the  spirit 
benzoline  comes  from  the  same  source. 


190  THE  FAIRY-LAND  OF  SCIENCE, 


From  benzoline,  again,  we  get  a  liquid  called  aniline, 
from  which  are  made  so  many  of  our  beautiful  dyes 
—  mauve,  magenta,  and  violet  ;  and  what  is  still  more 
curious,  the  bitter  almonds,  pear-drops,  and  many 
othei  sweets  which  children  like  so  well,  are  actually 
flavoured  by  essences  which  come  out  of  coal-tar. 
Thus  from  coal  we  get  not  only  nearly  all  our  heat 
and  our  light,  but  beautiful  colours  and  pleasant 
flavours.  We  spoke  just  now  of  the  plants  of  the  coal 
as  being  without  beautiful  flowers,  and  yet  we  see  that 
long,  long  after  their  death  they  give  us  lovely  colours 
and  tints  as  beautiful  as  any  in  flower-world  now. 

Think,  then,  how  much  we  owe  to  these  plants 
which  lived  and  died  so  long  ago !  If  they  had 
been  able  to  reason,  perhaps  they  might  have  said 
that  they  did  not  seem  of  much  use  in  the  world. 
They  had  no  pretty  flowers,  and  there  was  no  one  to 
admire  their  beautiful  green  foliage  except  a  few 
croaking  reptiles,  and  little  crickets  and  grasshoppers; 
and  they  lived  and  died  all  on  one  spot,  generation 
after  generation,  without  seeming  to  do  much  good  to 
anything  or  anybody.  Then  they  were  covered  up 
and  put  out  of  sight,  and  down  in  the  dark  earth 
they  were  pressed  all  out  of  shape  and  lost  their 
beauty  and  became  only  black,  hard  coal.  There 
they  lay  for  centuries  and  centuries,  and  thousands 
and  thousands  of  years,  and  still  no  one  seemed  to 
want  them. 

At  last,  one  day,  long,  long  after  man  had  been 
living  on  the  earth,  and  had  been  burning  wood  for 
fires,  and  so  gradually  using  up  the  trees  in  the  forests, 


A  PIECE  OF  COAL.  191 

it  was  discovered  that  this  black  stone  would  burn, 
and  from  that  time  coal  has  been  becoming  every  day 
more  and  more  useful.  Without  it  not  only  should 
we  have  been  without  warmth  in  our  houses,  or  light 
in  our  streets  when  the  stock  of  forest-wood  was  used 
up ;  but  we  could  never  have  melted  large  quantities 
of  iron-stone  and  extracted  the  iron.  We  have  proof 
of  this  in  Sussex.  The  whole  country  is  full  of  iron- 
stone, and  the  railings  of  St.  Paul's  churchyard  are 
made  of  Sussex  iron.  Iron-foundries  were  at  work 
there  as  long  as  there  was  wood  enough  to  supply 
them,  but  gradually  the  w^orks  fell  into  disuse,  and 
the  last  furnace  was  put  out  in  the  year  1809.  So  now, 
because  there  is  no  coal  in  Sussex,  the  iron  lies  idle; 
while  in  the  North,  where  the  ironstone  is  near  the 
coal-mines,  hundreds  of  tons  are  melted  out  every  day. 

Again,  without  coal  we  could  have  had  no  engines  of 
any  kind,  and  consequently  no  large  manufactories  of 
cotton  goods,  linen  goods,  or  cutlery.  In  fact,  almost 
everything  we  use  could  only  have  been  made  with 
difficulty  and  in  small  quantities  ;  and  even  if  we  could 
have  made  them  it  would  have  been  impossible  to 
have  sent  them  so  quickly  all  over  the  world  without 
coal,  for  we  could  have  had  no  railways  or  steamships, 
but  must  have  carried  all  goods  along  canals,  and  by 
slow  sailing  vessels.  We  ourselves  must  have  taken 
days  to  perform  journeys  now  made  in  a  few  hours, 
and  months  to  reach  our  colonies. 

In  consequence  of  this  we  should  have  remained  a 
very  poor  people.  Without  manufactories  and  in- 
dustries we  sliould  have  had  to  live  chiefly  by  tilling 
the  ground,  and  everyone  being  obliged  to  toil  foi 


ig2 


THE  FAIRY'LAND  OF  SCIENCE. 


their  daily  bread,  there  would  have  been  much  less 
time  or  opportunity  for  anyone  to  study  science,  or 
literature,  or  history,  or  to  provide  themselves  with 
comforts  and  refinements  of  life. 

All  this  then,  those  plants  and  trees  of  the  far-ofl 
ages,  which  seemed  to  lead  such  useless  lives,  have 
Jone  and  are  doing  for  us.  There  are  many  people 
in  the  world  who  complain  that  life  is  dull,  that  they 
do  not  see  the  use  of  it,  and  that  there  seems  no  work 
specially  for  them  to  do.  I  would  advise  such  people, 
whether  they  are  grown  up  or  little  children,  to  read 
the  story  of  the  plants  which  form  the  coal.  These 
saw  no  results  during  their  own  short  existences,  they 
only  lived  and  enjoyed  the  bright  sunshine,  and  did 
their  work,  and  were  content.  And  now  thousands, 
probably  millions,  of  years  after  they  lived  and  died, 
England  owes  her  greatness,  and  we  much  of  our 
happiness  and  comfort,  to  the  sunbeams  which  those 
plants  wove  into  their  lives. 

They  burst  forth  again  in  our  fires,  in  our  brilliant 
lights,  and  in  our  engines,  and  do  the  greater  part  ol 
our  work;  teaching  us 

*•  'I  hat  nothing  walks  with  aimless  feet, 
'I  hat  not  one  life  shall  be  destroyed, 
Or  cast  as  rubbish  to  the  void, 
When  God  hath  made  the  pile  complete." 

In  Mt-moriam^  Ut, 


BEES  IN  THE  HIVE, 


893 


LECTURE  IX. 


BEES  IN  THE  HIVE. 


beings  in  it,  and  yet  it  is  densely  populated,  for  such 
a  city  may  contain  from  twenty  thousand  to  sixty 
thousand  inhabitants.  In  it  you  will  find  streets, 
but  no  pavements,  for  the  inhabitants  walk  along 


IQ4 


THE  FAIRY-LAND  OF  SCIENCE, 


the  walls  of  the  houses ;  while  in  the  houses  you 
will  see  no  windows,  for  each  house  just  fits  its 
owner,  and  the  door  is  the  only  opening  in  it. 
Though  made  without  hands  these  houses  are  most 
evenly  and  regularly  built  in  tiers  one  above  the 
other ;  and  here  and  there  a  few  royal  palaces,  larger 
and  more  spacious  than  the  rest,  catch  the  eye  con- 
spicuously as  they  stand  out  at  the  corners  of  the 
streets. 

Some  of  the  ordinary  houses  are  used  to  live  in, 
wl  ile  others  serve  as  storehouses  where  food  is  laid  up 
in  the  summer  to  feed  the  inhabitants  during  the 
winter,  when  they  are  not  allowed  to  go  outside  the 
walls.  Not  that  the  gates  are  ever  shut  :  that  is  not 
necessary,  for  in  this  wonderful  city  each  citizen 
follows  the  laws  ;  going  out  when  it  is  time  to  go  out, 
coming  home  at  proper  hours,  and  staying  at  home 
when  it  is  his  or  her  duty.  And  in  the  winter,  when 
it  is  very  cold  outside,  the  inhabitants,  having  no  fires, 
keep  themselves  warm  within  the  city  by  clustering 
together,  and  never  venturing  out  of  doors. 

One  single  queen  reigns  over  the  whole  of  this 
numerous  population,  and  you  might  perhaps  fancy 
that,  having  so  many  subjects  to  work  for  her  and 
wait  upon  her,  she  would  do  nothing  but  amuse 
herself.  On  the  contrary,  she  too  obeys  the  laws 
laid  down  for  her  guidance,  and  never,  except  on  one 
or  two  state  occasions,  goes  out  of  the  city,  but  works 
as  hard  as  the  rest  in  performing  her  own  royal 
duties. 

From  sunrise  to  sunset,  whenever  thq  weather  is 
fine,  all  is  life,  activity,  and  bustle  in  this  busy  city 


BEES  IN  THE  HIVE. 


195 


Though  the  gates  are  so  narrow  that  two  inhabitants 
can  only  just  pass  each  other  on  their  way  through 
them,  yet  thousands  go  in  and  out  every  hour  of  the 
day  ;  some  bringing  in  materials  to  build  new  houses, 
others  food  and  provisions  to  store  up  for  the  winter ; 
and  while  all  appears  confusion  and  disorder  among 
this  rapidly  moving  throng,  yet  in  reality  each  has  her 
own  work  to  do,  and  perfect  order  reigns  over  the 
whole. 

Even  if  you  did  not  already  know  from  the  title  of 
the  lecture  what  city  this  is  that  I  am  describing,  you 
would  no  doubt  guess  that  it  is  a  beehive.  For  where 
in  the  whole  world,  except  indeed  upon  an  anthill,  can 
we  find  so  busy,  so  industrious,  or  so  orderly  a  com- 
munity as  among  the  bees  }  More  than  a  hundred 
years  ago,  a  blind  naturalist,  Francois  Huber,  set 
himself  to  stud}^  the  habits  of  these  wonderful  insects, 
and  with  the  help  of  his  wife  and  an  intelligent  man- 
servant managed  to  learn  most  of  their  secrets.  Before 
his  time  all  naturalists  had  failed  in  watching  bees, 
because  if  they  put  them  in  hives  with  glass  windows, 
the  bees,  not  liking  the  light,  closed  up  the  windows 
with  cement  before  they  began  to  work.  But  Huber 
invented  a  hive  which  he  could  open  and  close  at  will, 
putting  a  glass  hive  inside  it,  and  by  this  means  he 
was  able  to  surprise  the  bees  at  their  work.  Thanks 
to  his  studies,  and  to  those  of  other  naturalists  who 
have  followed  in  his  steps,  we  now  know  almost  as 
much  about  the  home  of  bees  as  we  do  about  our  own  ; 
and  if  we  follow  out  to-day  the  building  of  a  bee-city 
and  the  life  of  its  inhabitants,  I  think  you  will  acknow- 
ledge that  they  are  a  wonderful  community,  and  that 


196 


THE  FAIRY'LAND  OF  SCIENCE. 


it  is  a  great  compliment  to  anyone  to  say  that  he  01 
she  is  "  as  busy  as  a  bee." 

In  order  to  begin  at  the  beginning  of  the  story, 
let  us  suppose  that  we  go  into  a  country  garden 
one  fine  morning  in  May  when  the  sun  is  shining 
brightly  overhead,  and  that  we  see  hanging  from  the 
bough  of  an  old  apple-tree  a  black  object  which  looks 
very  much  like  a  large  plum-pudding.  On  approach- 
ing it,  however,  we  see  that  it  is  a  large  cluster  or 
swarm  of  bees  clinging  to  each  other  by  their  legs ; 
each  bee  with  its  two  fore-legs  clinging  to  the  two 
hinder  legs  of  the  one  above  it.  In  this  way  as  many 
as  20,000  bees  may  be  clinging  together,  and  yet  they 
hang  so  freely  that  a  bee,  even  from  quite  the  centre 
of  the  swarm,  can  disengage  herself  from  her  neigh- 
bours and  pass  through  to  the  outside  of  the  cluster 
whenever  she  wishes. 

If  these  bees  were  left  to  themselves,  they  would 
find  a  home  after  a  time  in  a  hollow  tree,  or  under 
the  roof  of  a  house,  or  in  some  other  cavity,  and  begin 
to  build  their  honeycomb  there.  But  as  we  do  not 
wish  to  lose  their  honey  we  will  bring  a  hive,  and, 
holding  it  under  the  swarm,  shake  the  bough  gently 
so  that  the  bees  fall  into  it,  and  cling  to  the  sides 
as  we  turn  it  over  on  a  piece  of  clean  linen,  on  the 
stand  where  the  hive  is  to  be. 

And  now  let  us  suppose  that  we  are  able  to  watch 
what  is  going  on  in  the  hive.  Before  five  minutes 
are  over  the  industrious  little  insects  have  begun  to 
disperse  and  to  make  arrangements  in  their  new  home. 
A  number  (perhaps  about  two  thousand)  of  large, 


BEES  IN  THE  HIVE, 


197 


lumbering  bees  of  a  darker  colour  than  the  rest,  will, 
it  is  true,  wander  aimlessly  about  the  hive,  and  wait  for 
the  others  to  feed  them  and  house  them  ;  but  these 
are  the  drones,  or  male  bees  (3,  Fig.  54),  who  never 
do  any  work  except  during  one  or  two  days  in  their 
whole  lives.  But  the  smaller  working  bees  (i.  Fig.  54) 
begin  to  be  busy  at  once.    Some  fly  off  in  search  of 

Fig.  54. 


I.  Worker  bee.    2.  Queen-bee.    3.  Drone  or  male  bee. 


honey.  Others  walk  carefully  all  round  the  inside  of 
the  hive  to  see  if  there  are  any  cracks  in  it ;  and  if 
there  are,  they  go  off  to  the  horse-chestnut  trees, 
poplars,  hollyhocks,  or  other  plants  which  have  sticky 
buds,  and  gather  a  kind  of  gum  called  "propolis," 
with  which  they  cement  the  cracks  and  make  them 
air-tight.  Others  again,  cluster  round  one  bee  (2,  Fig. 
54)  blacker  than  the  rest  and  having  a  longer  body  and 
shorter  wings  ;  for  this  is  the  queen-bee,  the  mother  of 
the  hive,  and  she  must  be  watched  and  tended. 

But  the  largest  number  begin  to  hang  in  a  cluster 
from  the  roof  just  as  they  did  from  the  bough  of  the 
apple  tree.   What  are  they  doing  there  t   Watch  for  a 
little  while  and  you  will  soon  see  one  bee  come  out 
14 


198  THE  FAIRY-LAND  OF  SCIENCE. 


from  among  its  companions  and  settle  on  the  top  of 

the  inside  of  the  hive,  turning  herself  round  and  round, 

so  as  to  push  the  other  bees  back,  and  to  make  a  space 

in  which  she  can  work.    Then  she  will  begin  to  pick 

at  the  under  part  of  her  body  with  her  fore-legs,  and 

will  bring  a  scale  of  wax  from  a  curious  sort  of  pocket 

under  her  abdomen.    Holding  this  wax  in  her  claws, 

she  will  bite  it  with  her  hard,  pointed  upper  jaws, 

which  move  to  and  fro  sideways  like  a  pair  of  pincers, 

then,  moistening  it  with  her  tongue  into  a  kind  of 

paste,  she  will  draw  it  out  like  a  ribbon  and  plaster  it 

on  the  top  of  the  hive. 

After  that  she  will  take  another  piece ;  for  she  has 

eight  of  these  little  wax-pockets,  and  she  will  go  on 

till  they  are  all  exhausted. 
Fig.  55.  . 

Then  she  will  fly  away  out 

of  the  hive,  leaving  a  small 
wax  lump  on  the  hive  ceil- 
ing or  on  the  bar  stretched 
across  it ;  then  her  place 
will  be  taken  by  another 
bee  who  will  go  through 
the  same  manoeuvres. 
This  bee  will  be  followed 
by  another,  and  another, 
till  a  large  wall  of  wax 
has  been  built,  hanging 
from  the  bar  of  the  hive  as  in  Fig.  55,  only  that  it 
will  not  yet  have  cells  fashioned  in  it. 

Meanwhile  the  bees  which  have  been  gathering 
honey  out  of  doors  begin  to  come  back  laden.  But 
they  cannot  store  their  honey,  for  there  are  no  cells 


Plate  of  wax  with  bases  of  cells, 
hanging  from  the  bar  of  a  hive. 


BEES  IN  THE  HIVE. 


199 


made  yet  to  put  it  in  ;  neither  can  they  build  combs 
with  the  rest,  for  they  have  no  wax  in  their  wax- 
pockets.  So  they  just  go  and  hang  quietly  on  to  the 
other  bees,  and  there  they  remain  for  twenty-four 
hours,  during  which  time  they  digest  the  honey  they 
have  gathered,  and  part  of  it  forms  wax  and  oozes 
out  from  the  scales  under  their  body..  Then  they 
are  prepared  to  join  the  others  at  work  and  plaster 
wax  on  to  the  hive. 

And  now,  as  soon  as  a  rough  lump  of  wax  is  ready, 
another  set  of  bees  come  to  do  their  work.  These  are 
called  the  nursing  bees,  because  they  prepare  the  cells 
and  feed  the  young  ones.  One  of  these  bees,  standing  on 
the  roof  of  the  hive,  begins  to  force  her  head  into  the 
wax,  biting  with  her  jaws  and  moving  her  head  to  and 
fro.  Soon  she  has  made  the  beginning  of  a  round 
hollow,  and  then  she  passes  on  to  make  another,  while 
a  second  bee  takes  her  place  and  enlarges  the  first 
one.  As  many  as  twenty  bees  will  be  employed  in 
this  way,  one  after  another,  upon  each  hole  before  it  is 
large  enough  for  the  base  of  a  cell. 

Meanwhile  another  set  of  nursing  bees  have  been 
working  just  in  the  same  way  on  the  other  side  of  the 
wax,  and  so  a  series  of  hollows  are  made  back  to  back 
all  over  the  comb.  Then  the  bees  form  the  walls  of 
the  cells,  and  soon  a  number  of  six-sided  tubes,  about 
half  an  inch  deep,  stand  all  along  each  side  of  the 
comb  ready  to  receive  honey  or  bee-eggs. 

Y ou  can  see  the  shape  of  these  cells  in  d,  Fig.  56,  and 
notice  how  closely  they  fit  into  each  other.  Even  the 
ends  are  so  shaped  that,  as  they  lie  back  to  back,  the 
bottom  of  one  cell  (b,  Fig.  56)  fits  into  the  space  between 


THE  FAIRY-LAND  OF  SCIENCE. 


the  ends  of  three  cells  meeting  it  from  the  opposite 
side  (a,  Fig.  56),  while  they  fit  into  the  spaces  around 
it.  Upon  this  plan  the  clever  little  bees  fill  eveiy 
atom  of  space,  use  the  least  possible  quantity  of  wax, 


Fig.  56. 


B  shows  in  the  centre  the  closed  end  of  a  cell  which  would  fit  into 
the  space  in  the  centre  of  the  three  closed  cells  in  A,  while  the  ends  of 
these  three  would  fit  into  the  spaces  in  B.    r,     side-view  of  cells. 

and  make  the  cells  lie  so  closely  together  that  the 
whole  comb  is  kept  warm  when  the  young  bees  are 
in  it. 

There  are  some  kinds  of  bees  who  do  not  live  in 
hives,  but  each  one  builds  a  home  of  its  own.  These 
bees — such  as  the  upholsterer  bee,  which  digs  a  hole  in 
the  earth  and  lines  it  with  flowers  and  leaves,  and  the 
mason  bee,  which  builds  in  walls — do  not  make  six- 
sided  cells,  but  round  ones,  for  room  is  no  object  to 
them.  But  nature  has  gradually  taught  the  little  hive- 
bee  to  build  its  cells  more  and  more  closely,  till  they 
fit  perfectly  within  each  other.  If  you  make  a  number 
of  round  holes  close  together  in  a  soft  substance,  and 
then  squeeze  the  substance  evenly  from  all  sides,  the 
rounds  will  gradually  take  a  six-sided  form,  showing 
that  this  is  the  closest  shape  into  which  they  can  be 
compressed.    Although  the  bee  does  not  know  this, 


BEES  IN  THE  HIVE. 


20 1 


yet  as  she  gnaws  away  every  bit  of  wax  that  can  be 
spared  she  brings  the  holes  into  this  shape. 

As  soon  as  one  comb  is  finished,  the  bees  begin 
another  by  the  side  of  it,  leaving  a  narrow  lane  between, 
just  broad  enough  for  two  bees  to  pass  back  to  back 
as  they  crawl  along,  and  so  the  work  goes  on  till  the 
hive  is  full  of  combs. 

As  soon,  however,  as  a  length  of  about  five  or  six 
inches  of  the  first  comb  has  been  made  into  cells, 
the  bees  which  are  bringing  home  honey  no  longer 
hang  to  make  it  into  wax,  but  begin  to  store  it  in  the 
cells.  We  all  know  where  the  bees  go  to  fetch  their 
honey,  and  how,  when  a  bee  settles  on  a  flower,  she 
thrusts  into  it  her  small  tongue-like  proboscis,  which 
is  really  a  lengthened  under-lip,  and  sucks  out  the 
drop  of  honey.  This  she  swallows,  passing  it  down 
her  throat  into  a  honey-bag  or  first  stomach,  which 
lies  between  her  throat  and  her  real  stomach,  and  when 
she  gets  back  to  the  hive  she  can  empty  this  bag  and 
pass  the  honey  back  through  her  mouth  again  into  the 
honey-cells. 

But  if  you  watch  bees  carefully,  especially  in  the 
spring-time,  you  will  find  that  they  carry  off  something 
else  besides  honey.  Early  in  the  morning,  when  the  dew 
is  on  the  ground,  or  later  in  the  day,  in  moist,  shady 
places,  you  may  see  a  bee  rubbing  itself  against  a  flower, 
or  biting  those  bags  of  yellow  dust  or  pollen  which  we 
mentioned  in  Lecture  VI 1.  When  she  has  covered 
herself  with  pollen,  she  will  brush  it  off  with  her  feet, 
and,  bringing  it  to  her  mouth,  she  will  moisten  and  roll 
it  into  a  little  ball,  and  then  pass  it  back  from  the  first 
pair  of  legs  to  the  second  and  so  to  the  third  or  hinder 


202 


THE  FAIRY-LAND  OF  SCIENCE. 


pair.  Here  she  will  pack  it  into  a  little  hairy  groove 
called  a  "basket"  in  the  joint  of  one  of  the  hind  legs, 
where  you  may  see  it,  looking  like  a  swelled  joint,  as 
she  hovers  among  the  flowers.  She  often  fills  both 
hind  legs  in  this  way,  and  when  she  arrives  back  at 
the  hive  the  nursing  bees  take  the  lumps  from  her,  and 
eat  it  themselves,  or  mix  it  with  honey  to  feed  the 
young  bees ;  or,  when  they  have  any  to  spare,  store  it 
away  in  old  honey-cells  to  be  used  by-and-by.  This 
is  the  dark,  bitter  stuff  called  "  bee-bread  "  which  you 
often  find  in  a  honeycomb,  especially  in  a  comb  which 
has  been  filled  late  in  the  summer. 

When  the  bee  has  been  relieved  of  the  bee-bread 
she  goes  off  to  one  of  the  clean  cells  in  the  new  comb, 
and,  standing  on  the  edge,  throws  up  the  honey  from 
the  honey-bag  into  the  cell.  One  cell  will  hold  the 
contents  of  many  honey-bags,  and  so  the  busy  little 
workers  have  to  work  all  day  filling  cell  after  cell,  in 
which  the  honey  lies  uncovered,  being  too  thick  and 
sticky  to  flow  out,  and  is  used  for  daily  food — unless 
there  is  any  to  spare,  and  then  they  close  up  the  cells 
with  wax  to  keep  for  the  winter. 

Meanwhile,  a  day  or  two  after  the  bees  have  settled 
in  the  hive,  the  queen-bee  begins  to  get  very  restless. 
She  goes  outside  the  hive  and  hovers  about  a  little 
while,  and  then  comes  in  again,  and  though  generally 
the  bees  all  look  very  closely  after  her  to  keep  her 
indoors,  yet  now  they  let  her  do  as  she  likes.  Again 
she  goes  out,  and  again  back,  and  then,  at  last,  she 
soars  up  into  the  air  and  flies  away.  But  she  is  not 
allowed  to  go  alone.    All  the  drones  of  the  hive  rise 


BEES  IN  THE  HIVE.  203 

up  after  her,  forming  a  guard  of  honour  to  follow  hei 
wherever  she  goes. 

In  about  half-an-hour  she  comes  back  again,  and 
then  the  working  bees  all  gather  round  her,  knowing 
that  now  she  will  remain  quietly  in  the  hive  and 
spend  all  her  time  in  laying  eggs  :  for  it  is  the  queen- 
bee  who  lays  all  the  eggs  in  the  hive.  This  she 
begins  to  do  about  two  days  after  her  flight.  There 
are  now  many  cells  ready  besides  those  filled  with 
honey :  and,  escorted  by  several  bees,  the  queen-bee 
goes  to  one  of  these,  and,  putting  her  head  into  it, 
remains  there  a  second  as  if  she  were  examining 
whether  it  would  make  a  good  home  for  the  young 
bee.  Then,  coming  out,  she  turns  round  and  lays  a 
small,  oval,  bluish-white  egg  in  the  cell.  After  this 
she  takes  no  more  notice  of  it,  but  goes  on  to  the  next 
ceil  and  the  next,  doing  the  same  thing,  and  laying 
eggs  in  all  the  empty  cells  equally  on  both  sides  of 
the  comb.  She  goes  on  so  quickly  that  she  some- 
times lays  as  many  as  200  eggs  in  one  day. 

Then  the  work  of  the  nursing  bees  begins.  In  two 
or  three  days  each  egg  has  become  a  tiny  maggot  or 
larva,  and  the  nursing  bees  put  into  its  cell  a  mixture 
of  pollen  and  honey  which  they  have  prepared  in  their 
own  mouths,  thus  making  a  kind  of  sweet  bath  in  which 
the  larva  lies.  In  five  or  six  days  the  larva  grows  so 
fat  upon  this  that  it  nearly  fills  the  cell,  and  then  the 
bees  seal  up  the  mouth  of  the  cell  with  a  thin  cover 
of  wax,  made  of  little  rings  and  with  a  tiny  hole  in  the 
centre. 

As  soon  as  the  larva  is  covered  in,  it  begins  to  give 
out  from  its  under-lip  a  whitish,  silken  film,  made  oi 


204  THE  FAIRY-LAND  OF  SCIENCE. 

two  threads  of  silk  glued  together,  and  with  this  it 
spins  a  covering  or  cocoon  all  round  itself,  and  so  it 
remains  for  about  ten  days  more.  At  last,  just  twenty- 
one  days  after  the  egg  was  laid,  the  young  bee  is  quite 
perfect,  lying  in  the  cell  as  in  Fig.  57,  and  she  begins 

to  eat  her  way  through  the 
cocoon  and  through  the 
waxen  lid,  and  scrambles 
out  of  her  cell.  Then  the 
nurses  come  again  to  her, 
stroke  her  wings  and  feed 
her  for  twenty-four  hours,  and 
after  that  she  is  quite  ready 
to  begin  work,  and  flics  out 
to  gather  honey  and  pollen 
like  the  rest  of  the  workers. 

By  this  time  the  number 
of  working  bees  in  the  hive 
is  becoming  very  great,  and 
the  storing  of  honey  and 
pollen  -  dust  goes  on  very 
quickly.  Even  the  empty 
cells  which  the  young  bees 
have  left  are  cleaned  out  by 
the  nurses  and  filled  with 
honey ;  and  this  honey  is 
darker  than  that  stored  in 
clean  cells,  and  which  we  always  call  virgin  honey  " 
because  it  is  so  pure  and  clear. 

At  last,  after  six  weeks,  the  queen  leaves  off  laying 
worker-eggs,  and  begins  to  lay,  in  some  rather  larger 
cells,  eggs  from  \A  hich  drones,  or  male  bees,  will  grow 


Fis.  57. 


Brood-comb  cut  open,  with  the 
pupae,  or  young  bees,  /,  />,  in 
the  cells. 


The  lower  cells  contain  egc^s, 
afterwards  to  become  bees. 
^,  a  royal  cell. 


BEES  IN  THE  HIVE, 


205 


up  111  about  twenty  days.  Meanwhile  the  worker-bees 
have  been  building  on  the  edge  of  the  cones  some 
very  curious  cells  {q,  Fig.  57)  which  look  like  thimbles 
hanging  with  the  open  side  upwards,  and  about  every 
three  days  the  queen  stops  in  laying  drone-eggs  and 
goes  to  put  an  egg  in  one  of  these  cells.  Notice  that 
she  waits  three  days  between  each  of  these  peculiar 
layings,  because  we  shall  see  presently  that  there  is  a 
good  reason  for  her  doing  so. 

The  nursing  bees  take  great  care  of  these  eggs,  and 
instead  of  putting  ordinary  food  into  the  cell,  they  fill 
it  with  a  sweet,  pungent  jelly,  for  this  larva  is  to 
become  a  princess  and  a  future  queen-bee.  Curiously 
enough,  it  seems  to  be  the  peculiar  food  and  the  size 
of  the  cell  which  makes  the  larva  grow  into  a  mother- 
bee  which  can  lay  eggs,  for  if  a  hive  has  the  mis- 
fortune to  lose  its  queen,  they  take  one  of  the  ordinary 
worker-larvae  and  put  it  into  a  royal  cell  and  feed  it 
with  jelly,  and  it  becomes  a  queen-bee.  As  soon  as  the 
princess  is  shut  in  like  the  others,  she  begins  to  spin 
her  cocoon,  but  she  does  not  quite  close  it  as  the  other 
bees  do,  but  leaves  a  hole  at  the  top. 

At  the  end  of  sixteen  days  after  the  first  royal 
egg  was  laid,  the  eldest  princess  begins  to  try  to  eat 
her  way  out  of  her  cell,  and  about  this  time  the 
old  queen  becomes  very  uneasy,  and  wanders  about 
distractedly.  The  reason  of  this  is,  that  there  can 
never  be  two  queen-bees  in  one  hive,  and  the  queen 
knows  that  her  daughter  will  soon  be  coming  out  of 
her  cradle  and  will  try  to  turn  her  off  her  throne. 
So,  not  wishing  to  have  to  fight  for  her  kingdom,  she 
makes  up  her  mind  to  seek  a  new  home  and  take  a 


2o6 


THE  FAIRY-LAND  OF  SCIENCE, 


number  of  her  subjects  with  her.  If  you  watch  the 
hive  about  this  time  you  will  notice  many  of  the  bees 
clustering  together  after  they  have  brought  in  their 
honey,  and  hanging  patiently,  in  order  to  have  plenty 
of  wax  ready  to  use  when  they  start,  while  the  queen 
keeps  a  sharp  look-out  for  a  bright,  sunny  day,  on 
which  they  can  swarm :  for  bees  will  never  swarm  on 
a  wet  or  doubtful  day  if  they  can  possibly  help  it,  and 
we  can  easily  understand  why,  when  we  consider  how 
the  rain  would  clog  their  wings  and  spoil  the  wax 
under  their  bodies. 

Meanwhile  the  young  princess  grows  very  impatient, 
and  tries  to  get  out  of  her  cell,  but  the  worker-bees 
drive  her  back,  for  they  know  there  would  be  a  terrible 
fight  if  the  two  queens  met.  So  they  close  up  the 
hole  she  has  made  with  fresh  wax  after  having  put  in 
some  food  for  her  to  live  upon  till  she  is  released. 

At  last  a  suitable  day  arrives,  and  about  ten  oi 
eleven  o'clock  in  the  morning  the  old  queen  leaves  the 
hive,  taking  with  her  about  2000  drones  and  from 
12,000  to  20.000  worker-bees,  which  fly  a  little  way 
clustering  round  her  till  she  alights  on  the  bough  ol 
some  tree,  and  then  they  form  a  compact  swarm  ready 
for  a  new  hive  or  to  find  a  home  of  their  own. 

Leaving  them  to  go  their  way,  we  will  now  return 
to  the  old  hive.  Here  the  liberated  princess  is 
reigning  in  all  her  glory ;  the  worker-bees  crowd 
round  her,  watch  over  her,  and  feed  her  as  thougli 
they  could  not  do  enough  to  show  her  honour.  But 
still  she  is  not  happy.  She  is  restless,  and  runs  about 
as  if  looking  for  an  enemy,  and  she  tries  to  get  at  the 
remaining  royal  cells  where  the  other  young  princesses 


BEES  IN  THE  HIVE, 


207 


are  still  shut  in.  But  the  workers  will  not  let  her 
touch  them,  and  at  last  she  stands  still  and  begins  to 
beat  the  air  with  her  wings  and  to  tremble  all  over, 
moving  more  and  more  quickly,  till  she  makes  quite  a 
loud,  piping  noise. 

Hark!  What  is  that  note  answering  her.?  It  is  a 
low,  hoarse  sound,  and  it  comes  from  the  cell  of  the 
next  eldest  princess.  Now  we  see  why  the  young 
queen  has  been  so  restless.  She  knows  her  sister  will 
soon  come  out,  and  the  louder  and  stronger  the  sound 
becomes  within  the  cell,  the  sooner  she  knows  the 
fight  will  have  to  begin.  And  so  she  makes  up  her 
mind  to  follow  her  mother's  example  and  to  lead  off 
a  second  swarm.  But  she  cannot  always  stop  to 
choose  a  fine  day,  for  her  sister  is  growing  very  strong 
and  may  come  out  of  her  cell  before  she  is  off.  And 
so  the  second,  or  after  swarm,  gets  ready  and  goes 
away.  And  this  explains  why  princesses'  eggs  are 
laid  a  few  days  apart,  for  if  they  were  laid  all  on  the 
same  day,  there  would  be  no  time  for  one  princess  to 
go  off  with  a  swarm  before  the  other  came  out  of  her 
cell.  Sometimes,  when  the  workers  are  not  watchful 
enough,  two  queens  do  meet,  and  then  they  fight  till 
one  is  killed  ;  or  sometimes  they  both  go  off  with  the 
same  swarm  without  finding  each  other  out.  But  this 
only  delays  the  fight  till  they  get  into  the  new  hive  ; 
sooner  or  later  one  must  be  killed. 

And  now  a  third  queen  begins  to  reign  in  the  old 
hive,  and  she  is  just  as  restless  as  the  preceding  ones, 
for  there  are  still  more  princesses  to  be  born.  But 
this  time,  if  no  new  swarm  wants  to  start,  the  workers 
do  not  try  to  protect  the  royal  cells.    The  young 


208  THE  FAIRY-LAND  OF  SCIENCE. 


queen  darts  at  the  first  she  sees,  gnaws  a  hole  with 
her  jaws,  and,  thrusting  in  her  sting  through  the  hole 
in  the  cocoon,  kills  the  young  bee  while  it  is  still  a 
prisoner.  She  then  goes  to  the  next,  and  the  next, 
and  never  rests  till  all  the  young  princesses  are  de- 
stroyed. Then  she  is  contented,  for  she  knows  no 
other  queen  will  come  to  dethrone  her.  After  a  few 
days  she  takes  her  flight  in  the  air  with  the  drones,  and 
comes  home  to  settle  down  in  the  hive  for  the  winter. 

Then  a  very  curious  scene  takes  place.  The  drones 
are  no  more  use,  for  the  queen  will  not  fly  out  again, 
and  these  idle  bees  will  never  do  any  work  in  the 
hive.  So  the  worker-bees  begin  to  kill  them,  falling 
upon  them,  and  stinging  them  to  death,  and  as  the 
drones  have  no  stings  they  cannot  defend  themselves, 
and  in  a  few  days  there  is  not  a  drone,  nor  even  a 
drone-egg,  left  in  the  hive.  This  massacre  seems  very 
sad  to  us,  since  the  poor  drones  have  never  done  any 
harm  beyond  being  hopelessly  idle.  But  it  is  less  sad 
when  we  know  that  they  could  not  live  many  weeks, 
even  if  they  were  not  attacked,  and,  with  winter 
coming,  the  bees  cannot  afi"ord  to  feed  useless  mouths, 
so  a  quick  death  is  probably  happier  for  them  than 
starvation. 

And  now  all  the  remaininc^  inhabitants  of  the  hive 
settle  down  to  feeding  the  young  bees  and  laying  in 
the  winter's  store.  It  is  at  this  time,  after  they  have 
been  toiling  and  saving,  that  we  come  and  take  their 
honey  ;  and  from  a  well-stocked  hive  we  may  even  take 
30  lbs.  without  starving  the  industrious  little  inhabi- 
tants.   But  then  we  must  often  feed  them  in  return. 


BEES  IN  THE  HIVE.  2Cg 

and  give  them  sweet  syrup  in  the  late  autumn  and  the 
next  early  spring  when  they  cannot  find  any  flowers. 

Although  the  hive  has  now  become  comparatively 
quiet  and  the  work  goes  on  without  excitement,  yet 
every  single  bee  is  employed  in  some  way,  either  out 
of  doors  or  about  the  hive.  Besides  the  honey  col- 
lectors and  the  nurses,  a  certain  number  of  bees  are 
told  off  to  ventilate  the  hive.  You  will  easily  under- 
stand that  where  so  many  insects  are  packed  closely 
together  the  heat  will  become  very  great,  and  the  air 
impure  and  unwholesome.  And  the  bees  have  no 
windows  that  they  can  open  to  let  in  fresh  air,  so  they 
are  obliged  to  fan  it  in  from  the  one  opening  of  the  hive. 
The  way  in  which  they  do  this  is  very  interesting. 
Some  of  the  bees  stand  close  to  the  entrance,  with 
their  faces  towards  it,  and  opening  their  wings,  so  as  to 
make  them  into  fans,  they  wave  them  to  and  fro, 
producing  a  current  of  air.  Behind  these  bees,  and  all 
over  the  floor  of  the  hive,  there  stand  others,  this  time 
with  their  backs  towards  the  entrance,  and  fan  in  the 
same  manner,  and  in  this  way  air  is  sent  into  all  the 
passages. 

Another  set  of  bees  clean  out  the  cells  after  the 
young  bees  are  born,  and  make  them  fit  to  receive 
honey,  while  others  guard  the  entrance  of  the  hive  to 
keep  away  the  destructive  wax-moth,  which  tries  to  lay 
its  eggs  in  the  comb  so  that  its  young  ones  may  feed 
on  the  honey.  All  industrious  people  have  to  guard 
their  property  against  thieves  and  vagabonds,  and  the 
bees  have  many  intruders,  such  as  wasps  and  snails 
and  slugs,  which  creep  in  whenever  they  get  a  chance. 
If  they  succeed  in  escaping  the  sentinel  bees,  then  a 


2IO  THE  FAIRY-LAND  OF  SCIENCE. 


fight  takes  place  within  the  hive,  and  the  invader  is 
stung  to  death. 

Sometimes,  however,  after  they  have  killed  the 
enemy,  the  bees  cannot  get  rid  of  his  body,  for  a  snail 
or  slug  is  too  heavy  to  be  easily  moved,  and  yet  it 
would  make  the  hive  very  unhealthy  to  allow  it  to 
remain.  In  this  dilemma  the  ingenious  little  bees 
fetch  the  gummy  "  propolis  "  from  the  plant-buds  and 
cement  the  intruder  all  over,  thus  embalming  his 
body  and  preventing  it  from  decaying. 

And  so  the  life  of  this  wonderful  city  goes  on. 
Building,  harvesting,  storing,  nursing,  ventilating  and 
cleaning  from  morn  till  night,  the  little  worker-bee 
lives  for  about  eight  months,  and  in  that  time  has 
done  quite  her  share  of  work  in  the  world.  Only  the 
young  bees,  born  late  in  the  season,  live  on  till  the 
next  year  to  work  in  the  spring.  The  queen-bee  lives 
longer,  probably  about  two  years,  and  then  she  too 
dies,  after  having  had  a  family  of  many  thousands  of 
children. 

We  have  already  pointed  out  that  in  our  fairy-land 
of  nature  all  things  work  together  so  as  to  bring  order 
out  of  apparent  confusion.  But  though  we  should 
naturally  expect  winds  and  currents,  rivers  and  clouds, 
and  even  plants  to  follow  fixed  laws,  we  should 
scarcely  have  looked  for  such  regularity  in  the  life 
of  the  active,  independent  busy  bee.  Yet  we  see  that 
she,  too,  has  her  own  appointed  work  to  do,  and  does 
it  regularly  and  in  an  orderly  manner.  In  this  lecture 
we  have  been  speaking  entirely  of  the  bee  within  the 
hive,  and  noticing  how  marvellously  her  instincts 
guide  her  in  her  daily  life.    But  within  the  last  few 


BEES  IN  THE  HIVE, 


21! 


years  we  have  learnt  that  she  performs  a  most  curious 
and  wonderful  work  in  the  world  outside  her  home, 
and  that  we  owe  to  her  not  only  the  sweet  honey  we 
eat,  but  even  in  a  great  degree  the  beauty  and  gay 
colours  of  the  flowers  which  she  visits  when  coUectinpf 
it.  This  work  will  form  the  subject  of  our  next 
lecture,  and  while  we  love  the  little  bee  for  her  con- 
stant industry,  patience,  and  order  within  the  hive, 
we  shall,  I  think,  marvel  at  the  wonderful  law  of 
nature  which  guides  her  in  her  unconscious  mission  oi 
love  among  the  flowers  which  grow  around  it. 


212 


THE  FAIRY-LAND  OF  SCIENCE 


LECTURE  X. 

^KES  AND  FLOWERS. 


I  want  you  to  throw  them  all  aside  and  fancy  yourself 
to  be  in  a  pretty  country  garden  on  a  hot  summer's 
morning.  Perhaps  you  have  been  walking,  or  read- 
ing, or  playing,  but  it  is  getting  too  hot  now  to  do 


BEES  AND  FLOWERS. 


213 


anything ;  and  so  you  have  chosen  the  shadiest  nook 
under  the  old  walnut-tree,  close  to  the  flower-bed  on 
the  lawn,  and  would  almost  like  to  go  to  sleep  if  it 
were  not  too  early  in  the  day. 

As  you  lie  there  thinking  of  nothing  in  particular,' 
except  how  pleasant  it  is  to  be  idle  now  and  then, 
you  notice  a  gentle  buzzing  close  to  you,  and  you  see 
that  on  the  flower-bed  close  by,  several  bees  are 
working  busily  among  the  flowers.  They  do  not  seem 
to  mind  the  heat,  nor  to  wish  to  rest ;  and  they  fly  so 
lightly  and  look  so  happy  over  their  work  that  it  does 
not  tire  you  to  look  at  them. 

That  great  humble-bee  takes  it  leisurely  enough  as 
she  goes  lumbering  along,  poking  her  head  into  the 
larkspurs,  and  remaining  so  long  in  each  you  might 
almost  think  she  had  fallen  asleep.  The  brown  hive- 
bee,  on  the  other  hand,  moves  busily  and  quickly 
among  the  stocks,  sweet  peas,  and  mignonette.  She 
is  evidently  out  on  active  duty,  and  means  to  get  all 
she  can  from  each  flower,  so  as  to  carry  a  good  load 
back  to  the  hive.  In  some  blossoms  she  does  not  stay 
a  moment,  but  draws  her  head  back  directly  she  has 
popped  it  in,  as  if  to  say,  "  No  honey  there."  But 
over  the  full  blossoms  she  lingers  a  little,  and  then 
scrambles  out  again  with  her  drop  of  honey,  and  goes 
off  to  seek  more  in  the  next  flower. 

Let  us  watch  her  a  little  more  closely.  There  are 
plenty  of  different  plants  growing  in  the  flower-bed, 
but,  curiously  enough,  she  does  not  go  first  to  one  kind 
and  then  to  another ;  but  keeps  to  one,  perhaps  the 
mignonette,  the  whole  time,  till  she  flies  away.  Rouse 
yourself  up  to  follow  her,  and  you  will  see  she  takes 

IS 


214  IHE  FAIRY'LAND  OF  SCIENCE. 


her  way  back  to  the  hive.  She  may  perhaps  stop  to 
visit  a  stray  plant  of  mignonette  on  her  way,  but  no 
other  flower  will  tempt  her  till  she  has  taken  her  load 
home. 

Then  when  she  comes  back  again  she  may  perhaps 
go  to  another  kind  of  flower,  such  as  the  sweet  peas, 
for  instance,  and  keep  to  them  during  the  next  journey, 
but  it  is  more  likely  that  she  will  be  true  to  her  old 
friend  the  mignonette  for  the  whole  day. 

We  all  know  why  she  makes  so  many  journeys 
between  the  garden  and  the  hive,  ar^d  that  she  is 
collecting  drops  of  honey  from  each  flower,  and  car- 
rying it  to  be  stored  up  in  the  honeycomb  for  winter  s 
food.  How  she  stores  it,  and  how  she  also  gathers 
pollen-dust  for  her  bee-bread,  we  saw  in  the  last 
lecture ;  to-day  we  will  follow  her  in  her  work  amonj^j 
the  flowers,  and  see,  while  they  are  so  useful  to  her, 
what  she  is  doing  for  them  in  return. 

We  have  already  learnt  from  the  life  of  a  primrose 
that  plants  can  make  better  and  stronger  seeds  when 
they  can  get  pollen-dust  from  another  plant,  than 
when  they  are  obliged  to  use  that  which  grows  in  the 
same  flower  ;  but  I  am  sure  you  will  be  very  much 
surprised  to  hear  that  the  more  we  study  flowers  the 
more  we  find  that  their  colours,  their  scent,  and  their 
curious  shapes  are  all  so  many  baits  and  traps  set  by 
nature  to  entice  insects  to  come  to  the  flowers,  and 
carry  this  pollen-dust  from  one  to  the  other. 

So  far  as  we  know,  it  is  entirely  for  this  purpose 
that  the  plants  form  honey  in  different  parts  of  the 
flower,  sometimes  in  little  bags  or  glands,  as  in  the 
petals  of  the  buttercup  flower,  sometimes  in  cleai 


BEES  AND  FLOWERS, 


215 


Jrops,  as  in  the  tube  of  the  honeysuckle.  This  food 
they  prepare  for  the  insects,  and  then  they  have  all 
sorts  of  contrivances  to  entice  them  to  come  and 
fetch  it. 

You  will  remember  that  the  plants  of  the  coal  had 
no  bright  or  conspicuous  flowers.  Now  we  can  under- 
stand why  this  was,  for  there  were  no  flying  insects 
at  that  time  to  carry  the  pollen-dust  from  flower  to 
flower,  and  therefore  there  was  no  need  of  coloured 
flowers  to  attract  them.  But  little  by  little,  as  flies, 
butterflies,  moths  and  bees  began  to  live  in  the  world, 
flowers  too  began  to  appear,  and  plants  hung  out  these 
gay-coloured  signs,  as  much  as  to  say,  Come  to  me, 
and  I  will  give  you  honey  if  you  will  bring  me  pollen- 
dust  in  exchange,  so  that  my  seeds  may  grow  healthy 
and  strong.'* 

We  cannot  stop  to  inquire  to-day  how  this  all 
gradually  came  about,  and  how  the  flowers  gradually 
put  on  gay  colours  and  curious  shapes  to  tempt  the 
insects  to  visit  them  ;  but  we  will  learn  something 
about  the  way  they  attract  them  now,  and  how  you 
may  see  it  for  yourselves  if  you  keep  your  eyes 
open. 

For  example,  if  you  watch  the  different  kinds  of 
grasses,  sedges  and  rushes,  which  have  such  tiny 
flowers  that  you  can  scarcely  see  them,  you  will  find 
that  no  insects  visit  them.  Neither  will  you  ever  find 
bees  buzzing  round  oak-trees,  nut-trees,  willows,  elms 
or  birches.  But  on  the  pretty  and  sweet-smelling 
apple  -  blossoms,  or  the  strongly  scented  lime-trees, 
you  will  find  bees,  wasps,  and  plenty  of  other 
insects. 


I  i  6  THE  FAIR  Y'LA  ND  OF  SCIENCE 


The  reason  of  this  is  that  grasses,  sedges,  rushes^ 
nut-trees,  willows,  and  the  others  we  have  mentioned, 
have  all  of  them  a  great  deal  of  pollen-dust,  and  as 
the  wind  blows  them  to  and  fro,  it  wafts  the  dust  from 
one  flower  to  another,  and  so  these  plants  do  not  want 
the  insects,  and  it  is  not  worth  their  while  to  give  out 
honey,  or  to  have  gaudy  or  sweet-scented  flowers  to 
attract  them. 

But  wherever  you  see  bright  or  conspicuous  flowers 
you  may  be  quite  sure  that  the  plants  want  the  bees 
or  some  other  winged  insect  to  come  and  carry  their 
pollen  for  them.  Snowdrops  hanging  their  white 
heads  among  their  green  leaves,  crocuses  with  their 
violet  and  yellow  flowers,  the  gaudy  poppy,  the  large- 
flowered  hollyhock  or  the  sunflower,  the  flaunting 
dandelion,  the  pretty  pink  willow-herb,  the  clustered 
blossoms  of  the  mustard  and  turnip  flowers,  the 
bright  blue  forget-me-not  and  the  delicate  little 
yellow  trefoil,  all  these  are  visited  by  insects,  which 
easily  catch  sight  of  them  as  they  pass  by  and  hasten 
to  sip  their  honey. 

Sir  John  Lubbock  has  shown  that  bees  are  not  only 
attracted  by  bright  colours,  but  that  they  even  know 
one  colour  from  another.  He  put  some  honey  on 
slips  of  glass  with  coloured  papers  under  them,  and 
when  he  had  accustomed  the  bees  to  find  the  honey 
always  on  the  blue  glass,  he  washed  this  glass  clean, 
and  put  the  honey  on  the  red  glass  instead.  Now  if 
the  bees  had  followed  only  the  smell  of  the  honey, 
they  would  have  flown  to  the  red  glass,  but  they  did 
not.    They  went  first  to  the  blue  glass,  expecting  to 


BEES  AND  FLOWERS, 


217 


find  the  honey  on  the  usual  colour,  and  it  was  onlv 
when  they  were  disappointed  that  they  went  off  to 
the  red. 

Is  it  not  beautiful  to  think  that  the  bright  pleasant 
colours  we  love  so  much  in  flowers,  are  not  only  orna- 
mental, but  that  they  are  useful  and  doing  their  part 
in  keeping  up  healthy  life  in  our  world  ? 

Neither  must  we  forget  what  sweet  scents  can  do. 
Have  you  never  noticed  the  delicious  smell  which 
comes  from  beds  of  mignonette,  thyme,  rosemary,  mint, 
or  sweet  alyssum,  from  the  small  hidden  bunches  of 
laurustinus  blossom,  or  from  the  tiny  flowers  of  the 
privet  ?  These  plants  have  found  another  way  of 
attracting  the  insects  ;  they  have  no  need  of  bright 
colours,  for  their  scent  is  quite  as  true  and  certain  a 
guide.  You  will  be  surprised  if  you  once  be^^in  to 
count  them  up,  how  many  white  and  dull  or  dark- 
looking  flowers  are  sweet-scented,  while  gaudy  (iowers, 
such  as  the  tulip,  foxglove  and  hollyhock,  hr/ve  little 
or  no  scent.  And  then,  just  as  in  the  world  we  find 
some  people  who  have  everything  to  attract  ethers  to 
them,  beauty  and  gentleness,  cleverness,  kindb'ness,  and 
loving  sympathy,  so  we  find  some  flowers,  like  the 
beautiful  lily,  the  lovely  rose,  and  the  delicate  hyacinth, 
which  have  colour  and  scent  and  graceful  shapes  all 
combined* 

But  we  are  not  yet  nearly  at  an  end  of  the  contri- 
vances of  flowers  to  secure  the  visits  of  insects.  Have 
you  not  observed  that  different  flowers  open  and  close 
at  different  times  }  The  daisy  receives  its  name  day's 
eyey  because  it  opens  at  sunrise  and  closes  at  sunset, 


2l8 


THE  FAIRY  LAND  OF  SCIENCE, 


while  the  evening  primrose  {CEnothera  biennis)  and 
the  night  campion  {^Silene  noctijiora)  spread  out  their 
flowers  just  as  the  daisy  is  going  to  bed. 

What  do  you  think  is  the  reason  of  tliis  ?  If  you 
go  near  a  bed  of  evening  primroses  just  when  the  sun 
is  setting,  you  will  soon  be  able  to  guess,  for  they  will 
then  give  out  such  a  sweet  scent  that  you  will  not 
doubt  for  a  moment  that  they  are  calling  the  evening 
moths  to  come  and  visit  them.  The  daisy  opens  by 
day,  because  it  is  visited  by  day  insects,  but  those 
particular  moths  which  can  carry  the  pollen- dust  of 
the  evening  primrose,  fly  only  by  night,  and  if  this 
flower  opened  by  day  other  insects  might  steal  its 
honey,  while  they  would  not  be  the  ri^lit  size  or  shape 
to  touch  its  pollen-bags  and  carry  the  dust. 

It  is  the  same  if  you  pass  by  a  hon  ysuckle  in  the 
evening  ;  you  will  be  surprised  how  much  stronger  its 
scent  is  than  in  the  day-time.  This  is  because  the 
sphinx  hawk-moth  is  the  favourite  visitor  of  that 
flower,  and  comes  at  nightfall,  guided  by  the  strong 
scent,  to  suck  out  the  honey  with  its  long  proboscis, 
and  carry  the  pollen-dust. 

Again,  some  flowers  close  whenever  rain  is  coming. 
The  pimpernel  {Anagallis  arvensis)  is  one  of  these, 
hence  its  name  of  the  '*  Shepherd's  Weather-glass." 
This  little  flower  closes,  no  doubt,  to  prevent  its 
pollen-dust  being  washed  away,  for  it  has  no  honey  ; 
while  other  flowers  do  it  to  protect  the  drop  of  honey 
at  the  bottom  of  their  corolla.  Look  at  the  daisies 
for  example  when  a  storm  is  coming  on  ;  as  the  sky 
grows  dark  and  heavy,  you  will  see  them  shrink  up 
and  close  till  the  sun  shines  again.    They  do  tliis 


BEES  AND  FLOWERS, 


219 


because  in  each  of  the  little  yellow  florets  in  the 
centre  of  the  flower  there  is  a  drop  of  honey  which 
would  be  quite  spoiled  if  it  were  washed  by  the  rain. 

And  now  you  will  see  why  cup-shaped  flowers  so 
often  droop  their  heads — think  of  the  harebell,  the 
snowdrop,  the  li!y-of-the-valley,  the  campanula,  and 
a  host  of  others  ;  how  pretty  they  look  with  their 
bells  hanging  so  modestly  from  the  slender  stalk  ! 
They  are  bending  down  to  protect  the  honey-glands 
within  them,  for  if  the  cup  became  full  of  rain  or  dew 
the  honey  would  be  useless,  and  the  insects  would 
cease  to  visit  them. 

But  it  is  not  only  necessary  that  the  flowers  should 
keep  their  honey  for  the  insects,  they  also  have  to 
take  care  and  keep  it  for  the  right  kind  of  insect 
Ants  are  in  many  cases  great  enemies  to  them,  for 
they  like  honey  as  much  as  bees  and  butterflies  do^ 
yet  you  will  easily  see  that  they  are  so  sniall  that  if 
they  creep  into  a  flower  they  pass  the  anthers  without 
rubbing  against  them,  and  so  take  the  honey  without 
doing  any  good  to  the  plant  Therefore  we  find 
numberless  contrivances  for  keeping  the  ants  and  other 
creeping  insects  away.  Look  for  example  at  the  hairy 
stalk  of  the  primrose  flower  ;  those  little  hairs  are  like 
a  forest  to  a  tiny  ant,  and  they  protect  the  flower  from 
his  visits.  The  Spanish  catchfly  {Silene  otites),  on  the 
other  hand,  has  a  smooth,  but  very  gummy  stem,  and 
on  this  the  insects  stick,  if  they  try  to  climb.  Slugs 
and  snails  too  will  often  attack  and  bite  flowers,  unless 
they  are  kept  away  by  thorns  and  bristles,  such  as  we 
find  on  the  teazel  and  the  burdock.  And  so  we  are 
gradually  learning  that  everything  which  a  plant  does 


220  THE  FAIRY-LAND  OF  SCIENCE. 


has  its  meaning,  if  we  can  only  find  it  out,  and  that 
even  every  insignificant  hair  has  its  own  proper  use,  and 
when  we  are  once  aware  of  this  a  flower-garden  may 
become  quite  a  new  world  to  us  if  we  open  our  eyes  to 
all  that  is  going  on  in  it. 

But  as  we  cannot  wander  among  many  plants  to- 
day, let  us  take  a  few  which  the  bees  visit,  and  see 
how  they  contrive  not  to  give  up  their  honey  without 
getting  help  in  return.  We  will  start  with  the  blue 
wood-geranium,  because  from  it  we  first  began  to 
learn  the  use  of  insects  to  flowers. 

More  than  a  hundred  years  ago  a  young  German 
botanist,  Christian  Conrad  Sprengel,  noticed  some  soft 
hairs  growing  in  the  centre  of  this  flower,  just  round 
the  stamens,  and  he  was  so  sure  that  every  part  of  a 
plant  is  useful,  that  he  set  himself  to  find  out  what 
these  hairs  meant.  He  soon  discovered  that  they 
protected  some  small  honey-bags  at  the  base  of  the 
stamens,  and  kept  the  rain  from  washing  the  honey 
away,  just  as  our  eyebrows  prevent  the  perspiration 
on  our  faces  from  running  into  our  eyes.  This  led 
him  to  notice  that  plants  take  great  care  to  keep  their 
honey  for  insects,  and  by  degrees  he  proved  that  they 
did  this  in  order  to  tempt  the  insects  to  visit  them 
and  carry  off  their  pollen. 

The  first  thing  to  notice  in  this  little  geranium 
flower  is  that  the  purple  lines  which  ornament  it  all 
point  directly  to  the  place  where  the  honey  lies  at 
the  bottom  of  the  stamens,  and  actually  serve  to  lead 
tlie  bee  to  the  honey  ;  and  this  is  true  of  the  veins 
and  marking  of  nearly  all  flowers  except  of  those 


BEES  AND  FLOWERS. 


221 


Fig.  58. 


which  open  by  night,  and  in  these  they  would  be  useless , 
for  the  insects  would  not  see  them. 

When  the  geranium  first  opens,  all  its  ten  stamens 
are  lying  flat  on  the  corolla  or  coloured  crown,  as  in 
the  left-hand  flower  in  Fig.  58,  and  then  the  bee 
cannot  get  at  the 
honey.  But  in  a 
short  time  five  sta- 
mens begin  to  raise 
themselves  and  cling 
round  the  stigma  or 
knob  at  the  top  of  the 
seed-vessel,  as  in  the 
middle  flower.  Now 
you  would  think  they 
would  leave  their  dust 
there.  But  no !  the 
stigma  is  closed  up 
so  tight  that  the  dust 
cannot  get  on  to  the 
sticky  part.  Now, 
however,  the  bee  can 
get  at  the  honey- 
glands  on  the  out- 
side of  the 
stamens  ;  and  as  he 
sucks   it,   his  back 

touches  the  anthers  or  dust-bags,  and  he  carries  off"  the 
pollen.  Then,  as  soon  as  all  their  dust  is  gone,  these 
five  stamens  fall  down,  and  the  other  five  spring 
up.  Still,  however,  the  stigma  remains  closed,  and 
the  pollen  of  these  stamens,  too,  may  be  carried  away 


Geranhim  sylvaticum^  tte  Wood 
Geranium. 

In  the  left-hand  flower  the  stamens  are 
all  lying  down.  In  the  middle  flower  five 
raised   stamens  clasp  the  stigma.    In  the  right- 
hand  flower  the  stigma  is  open  after  all 
the  stamens  have  fallen. 


222  THE  FAIRY-LAND  DF  SCIENCE, 


to  another  flower.  At  last  these  five  also  fall  down, 
and  then,  and  not  till  then,  the  stigma  opens  and  lays 
out  its  five  sticky  points,  as  you  may  see  in  the  right- 
hand  flower,  Fig.  58. 

But  its  own  pollen  is  all  gone,  how  then  will  it  get 
any  ?  It  will  get  it  from  some  bee  who  has  just  taken  it 
from  another  and  younger  flower ;  and  thus  you  see  the 
blossom  is  prevented  from  using  its  own  pollen,  and 
made  to  use  that  of  another  blossom,  so  that  its  seeds 
may  grow  healthy  and  strong. 

The  garden  nasturtium,  into  whose  blossom  we  saw 
the  humble-bee  poking  his  head,  takes  still  more  care 
of  its  pollen-dust.  It  hides  its  honey  down  at  the  end 
of  its  long  spur,  and  only  sends  out  one  stamen  at  a 
time  instead  of  five  like  the  geranium  ;  and  then, 
when  all  the  stamens  have  had  their  turn,  the 
sticky  knob  comes  out  last  for  pollen  from  another 
flower. 

All  this  you  may  see  for  yourselves  if  you  find 
geraniums*  in  the  hedges,  and  nasturtiums  in  your 
garden.  But  even  if  you  have  not  these,  you  may 
learn  the  history  of  another  flower  quite  as  curious, 
and  which  you  can  find  in  any  field  or  lane  even  near 
London.  The  common  dead-nettle  (Fig.  59)  takes  a 
great  deal  of  trouble  in  order  that  the  bee  may  carry 
off  its  pollen.  When  you  have  found  one  of  these 
plants,  take  a  flower  from  the  ring  all  round  the  stalk 
and  tear  it  gently  open,  so  that  you  can  see  down 
its  throat.    There,  just  at  the  very  bottom,  you  will 

*  The  scarlet  and  other  bright  geraniums  of  our  flower-gardens  are 
not  true  geraniums,  but  pelargoniums.  You  may,  however,  watch  all 
these  peculiarities  in  them  if  you  cannot  procure  the  true  wild  geranium. 


BEES  AND  FLOWERS. 


223 


find  a  thick  fringe  of  hairs  (/,  No.  2,  Fig.  59),  and 
you  will  guess  at  once  that  these  are  to  protect  a 
drop  of  honey  below.    Little  insects  which  would 


Fig.  59. 


Flower  of  the  Dead-Nettie  {Lamium  album), 

I,  Whole.    2,  Cut  in  half. 
/,  Fringe  of  hairs  protecting  honey  at  base.    J,  Stigma, 
d!,  Anthers  of  stamens.    /,  Lip  of  flower. 


creep  into  the  flower  and  rob  it  of  its  honey  without 
touching  the  anthers  of  the  stamens  Fig.  59) 
cannot  get  past  these  hairs,  and  so  the  drop  is  kept 
till  the  bee  comes  to  fetch  it. 

Now  look  for  the  stamens :  there  are  four  of  them 
{a  a)y  two  long  and  two  short,  and  they  are  quite 


224 


THE  FAIRY-LAND  OF  SCIENCE. 


hidden  under  the  hood  which  forms  the  top  of  the 
flower.  How  will  the  bee  touch  them?  If  you  were 
to  watch  one,  you  would  find  that  when  the  bee 
alights  on  the  broad  Hp  /,  and  thrusts  her  head  down 
the  tube,  she  first  of  all  knocks  her  back  against  the 
little  forked  tip  s.  This  is  the  sticky  stigma,  and  she 
leaves  there  any  dust  she  has  brought  from  another 
flower;  then,  as  she  must  push  far  in  to  reach  the  honey, 
she  rubs  the  top  of  her  back  against  the  anthers  a  a,  and 
before  she  comes  out  again  has  carried  away  the 
yellow  powder  on  her  back,  ready  to  give  it  to  the 
next  flower. 

Do  you  remember  how  we  noticed  at  the  beginning 
of  the  lecture  that  a  bee  always  likes  to  visit  the  same 
kind  of  plant  in  one  journey  ?  You  see  now  that 
this  is  very  useful  to  the  flowers.  If  the  bee  went 
from  a  dead-nettle  to  a  geranium,  the  dust  would  be 
lost,  for  it  would  be  of  no  use  to  any  other  plant  but  a 
dead-nettle.  But  since  the  bee  likes  to  get  the  same 
kind  of  honey  each  journey,  she  goes  to  the  same  kind 
of  flowers,  and  places  the  pollen-dust  just  where  it  is 
wanted. 

There  is  another  flower,  called  the  Salvia,  which 
belongs  to  the  same  family  as  our  dead-nettle,  and  I 
think  you  will  agree  with  me  that  its  way  of  dusting 
the  bee  s  back  is  most  clever.  The  Salvia  (Fig.  60)  is 
shaped  just  like  the  dead-nettle,  with  a  hood  and  a 
broad  lip,  but  instead  of  four  stamens  it  has  only  two, 
the  other  two  being  shrivelled  up.  The  two  that  are 
left  have  a  very  strange  shape,  for  the  stalk  or 
filament  of  the  stamen  (i/)  is  very  short,  while  the 
anther,  which  is  in  most  flowers  two  little  bags  stuck 


BEES  AND  FLOWERS. 


225 


together,  has  here  grown  out  into  a  long  thread  a  b, 
with  a  little  dust-bag  at  one  end  only.  In  i,  Fig.  60, 
you  only  see  one  of  these  stems,  because  the  flower  is 


Fig.  60. 


Flower  of  the  Salvia. 


I,  Half  a  flower,  showing  the  filament  /,  the  swinging  anther  a 
b'  a\  and  the  stigma  s,    2.  Bee  entering  the  flower  pushes  the  anther  so 
that  it  takes  the  position  a!  b\  No.  i,  and  hits  him  on  the  back. 
3.  Older  flower  :  stigma  touching  the  bee. 

cut  in  half,  but  in  the  whole  flower,  one  stands  on 
each  side  just  within  the  lip.  Now,  when  the  bee 
puts  her  head  into  the  tube  to  reach  the  honey,  she 
passes  right  between  these  two  swinging  anthers,  and 
knocking  against  the  end  b  pushes  it  before  her  and 
so  brings  the  dust-bag  a  plump  down  on  her  back, 
scattering  the  dust  there !  You  can  easily  try  this  by 
thrusting  a  pencil  into  any  Salvia  flower,  and  you  will 
see  the  anther  fall. 

Yon  will  notice  that  all  this  time  the  bee  does  not 
touch  the  sticky  stigma  which  hangs  high  above  her  ^ 


226  THE  FAIRY-LAND  OF  SCIENCE, 


but  after  the  anthers  are  empty  and  shrivelled  the 
stalk  of  the  stigma  grows  longer,  and  it  falls  lower 
down.  By-and-by  another  bee,  having  pollen  on 
her  back,  comes  to  look  for  honey,  and  as  she  goes 
into  No.  3,  she  rubs  against  the  stigma  and  leaves 
upon  it  the  dust  from  another  flower. 

Tell  me,  has  not  the  Salvia,  while  remaining  so 
much  the  same  shape  as  the  dead-nettle,  devised  a 
wonderful  contrivance  to  make  use  of  the  visits  of  the 
bee } 

The  common  sweet  violet  ( Viola  odor  aid)  or  the  dog 
violet  ( Viola  caimid),  which  you  can  gather  in  any 
meadow,  give  up  their  pollen-dust  in  quite  a  different 
way  from  the  Salvia,  and  yet  it  is  equally  ingenious. 
Everyone  has  noticed  what  an  irregular  shape  this 
flower  has,  and  that  one  of  its  purple  petals  has  a 
curious  spur  sticking  out  behind.  In  the  tip  of  this 
spur  and  in  the  spur  of  the  stamen  lying  in  it  the 
violet  hides  its  honey,  and  to  reach  it  the  bee  must 
press  past  the  curious  ring  of  orange-tipped  bodies  in 
the  middle  of  the  flower.  These  bodies  are  the  anthers 
aa^  Fig.  6i,  which  fit  tightly  round  the  stigma  j",  so  that 
when  the  pollen-dust  which  is  very  dry,  comes  out 
of  the  bags,  it  remains  shut  in  by  the  tips  as  if  in  a 
box.  Two  of  these  stamens  have  spurs  which  in 
the  coloured  spur  of  the  flower,  and  have  honey  at  rAe 
end  of  them.  Now,  when  the  bee  shakes  the  end  of 
the  stigma  s,  it  parts  the  ring  of  anthers,  and  the  fine 
dust  falls  through  upon  the  insect. 

Let  us  see  foramomenthow  wonderfully  this  flower 
is  arranged  to  bring  about  the  carrying  of  the  pollen, 
i.s  Sprengel  pointed  out  years  ago.    In  the  first  place, 


BEES  AND  FLOWERS, 


227 


it  hangs  on  a  thin  stalk,  and  bends  its  head  down  so 
that  the  rain  cannot  come  near  the  honey  in  the  spur, 
and  also  so  that  the  pollen-dust  falls  forward  into  the 

Fig.  61. 


Section  of  the  Dog  Violet.  Lubbock. 

A,  A^nthers  and  stigma  enlarged,    a  a,  Anthers,    j,  Stigma. 
/,  Pollen.    ^,  Honey. 

front  of  the  little  box  made  by  the  closed  anthers. 
Then  the  pollen  is  quite  dry,  instead  of  being  sticky 
as  in  most  plants.  This  is  in  order  that  it  may  fall 
easily  through  the  crackr».  Then  the  style  or  stalk 
of  the  stigma  is  very  thin  and  its  tip  very  broad,  so 
that  it  quivers  easily  when  the  bee  touches  it,  and  so 
shakes  the  anthers  apart,  while  the  anthers  them- 
selves fold  over  to  make  the  box,  and  yet  not  so 
Rightly  but  that  the  dust  can  fall  through  when  they 


228 


THE  FAIRY-LAND  OF  SCIENCE. 


are  shaken.  Lastly,  if  you  look  at  the  veins  of  the 
flower,  you  will  find  that  they  all  point  towards  the 
spur  where  the  honey  is  to  be  found,  so  that  when 
the  sweet  smell  of  the  flower  has  brought  the  bee, 
she  cannot  fail  to  go  in  at  the  right  place. 

Two  more  flowers  still  I  want  us  Ao  examine 
together,  and  then  I  hope  you  will  care  to  look  at 
every  flower  you  meet,  to  try  and  see  what  insects 
visit  it,  and  how  its  pollen-dust  is  carried.  These  two 
flowers  are  the  common  Bird's-foot  trefoil  {Lotus 
corfticiclattis),  and  the  Early  Orchis  [Orchis  masculd)^ 
which  you  m.ay  find  in  almost  any  moist  meadow  in 
the  spring  and  early  summer. 

The  Bird's-foot  trefoil,  Fig.  62,  you  will  find  almost 
anywhere  all  through  the  summer,  and  you  will  know 
it  from  other  flowers  very  like  it  by  its  leaf,  which  is 
not  a  true  trefoil,  for  behind  the  three  usual  leaflets 
of  the  clover  and  the  shamrock  leaf,  it  has  two  small 
leaflets  near  the  stalk.  The  flower,  you  will  notice, 
is  shaped  very  like  the  flower  of  a  pea,  and  indeed  it 
belongs  to  the  same  family,  called  the  Papilionacece  or 
butterfly  family,  because  the  flowers  look  something 
like  an  insect  flying. 

In  all  these  flowers  the  top  petal  {sta^  Fig.  62) 
stands  up  like  a  flag  to  catch  the  eye  of  the  insect, 
and  for  this  reason  botanists  call  it  the  "standard." 
Below  it  are  two  side-petals  w  called  the  "wings,"  and 
if  you  pick  these  off  you  will  find  that  the  remaining 
two  petals  k  are  joined  together  at  the  tip  in  a  shape 
like  the  keel  of  a  boat  (2,  Fig.  62).  For  this  reason 
they  are  called  the  "  keel."  Notice  as  we  pass  that 
these  two  last  petals  have  in  them  a  curious  little 


BEES  AND  FLOWERS. 


22g 


hollow  or  depression  and  if  you  look  inside  the 
''wings"  you  will  notice  a  little  knob  that  fits  into 
this  hollow,  and  so  locks  the  two  together.  We  shall 
see  by~and-by  that  this  is  important 


Fig.  62. 


■a 


Lotus  corniculahis^  Bird's-foot  Trefoil. 

I.  Full  flower:  sta^  Standard;       Wings;       Keel.     2.  Keel  of 
flower:       Depression  into  which  wings  fit,    3.  Interior  of  flower: 
Stigma ;      Pollen ;      Anthers ;      Place  where  honey  lies. 

Next  let  us  look  at  the  half-flower  when  it  is  cut 
open,  and  see  what  there  is  inside.  There  are  ten 
stamens  in  all,  enclosed  with  the  stigma  in  the  keel ; 
nine  are  joined  together  and  one  is  by  itself.  The 
anthers  of  five  of  these  stamens  burst  open  while  the 
flower  is  still  a  bud,  but  the  other  stamens  go  on  grow- 
ing, and  push  the  pollen-dust,  which  is  very  moist 
16 


230  THE  E AIRY -LAND  OF  SCIENCE. 


and  sticky,  right  up  into  the  tip  of  the  keel.  Here 
you  see  it  lies  right  round  the  stigma  Sy  but  as  we 
saw  before  in  the  geranium,  the  stigma  is  not  ripe 
and  sticky  yet,  and  so  it  does  not  use  the  pollen- 
grains. 

Now  suppose  that  a  bee  comes  to  the  flower.  The 
honey  she  has  to  fetch  lies  inside  the  tube  at  h,  and 
the  one  stamen  being  loose  she  is  able  to  get  her 
proboscis  in.  But  if  she  is  to  be  of  any  use  to  the 
flower  she  must  uncover  the  pollen-dust.  See  how 
cunningly  the  flower  has  contrived  this.  In  order  to 
put  her  head  into  the  tube  the  bee  must  stand  upon 
the  wings  w,  and  her  weight  bends  them  down.  But 
they  are  locked  to  the  keel  k  by  the  knob  fitting  in 
the  hole  and  so  the  keel  is  pushed  down  too,  and 
the  sticky  pollen-dust  is  uncovered  and  comes  right 
against  the  stomach  of  the  bee  and  sticks  there  !  As 
soon  as  she  has  done  feeding  and  flies  away,  up  go 
the  wings  and  the  keel  with  them,  covering  up  any 
pollen  that  remains  ready  for  next  time.  Then  when 
the  bee  goes  to  another  flower,  as  she  touches  the 
stigma  as  well  as  the  pollen,  she  leaves  some  of  the 
foreign  dust  upon  it,  and  the  flower  uses  that  rather 
than  its  own,  because  it  is  better  for  its  seeds.  If 
however  no  bee  happens  to  come  to  one  of  these 
flowers,  after  a  time  the  stigma  becomes  sticky  and  it 
uses  its  own  pollen  :  and  this  is  perhaps  one  reason 
why  the  birds-foot  trefoil  is  so  very  common,  because 
it  can  do  its  own  work  if  the  bee  does  not  help  it. 

Now  we  come  lastly  to  the  Orchis  flower.  Mr. 
Darwin  has  written  a  whole  book  on  the  many 
curious  and  wonderful  ways  in  which  orchids  tempt 


BEES  AND  FLOWERS. 


233 


bees  and  othei  insects  to  fertilize  them.  We  can  only 
take  the  simplest,  but  I  think  you  will  say  that  even 
this  blossom  is  more  like  a  conjuror's  box  than  you 
would  have  supposed  it  possible  that  a  flowV  could  be. 

Let  us  examine  it  closely.  It  has  six  deep-red 
covering  leaves,  three  ccc,  Fig.  63,  belonging  to  the 


Fig.  63. 


Orchis  mascula, 

c  c  Calyx,  co^  co^  cOy  Corolla.  /,  Pollen-masses,  r,  Rostellum 
or  lid  covering  the  knob  at  the  end  of  pollen-masses,  s  s,  Stigmas. 
P,  a  Pollinia  or  pollen-mass,  of  which  a  is  the  pollen  and  d  the  sticky 
gland  which  adheres  to  the  head  of  the  bee.  sv.  Seed-vessel,  sp^  Spur 
of  the  flower. 

calyx  or  outer  cup,  and  three  cOy  cOy  cOy  belonging  to 
the  corolla  or  crown  of  the  flower ;  but  all  six  are 
coloured  alike,  except  that  the  large  one  in  front, 


232  THE  FAIRY-LAND  OF  SCIENCE. 


called  the  "lip/' has  spots  and  lines  upon  it  which  will 
suggest  to  you  at  once  that  they  point  to  the  honey. 

But  where  are  the  anthers,  and  where  is  the  stigma  ? 
Look  just  under  the  arch  made  by  those  three 
bending  flower-leaves,  and  there  you  will  see  two 
small  slits,  and  in  these  some  little  club-shaped  bodies 
p /,  which  you  can  pick  out  with  the  point  of  a  needle. 
One  of  these  enlarged  is  shown  at  P.  It  is  composed 
of  sticky  grains  of  pollen  a  held  together  by  fine 
threads  on  the  top  of  a  thin  stalk  ;  and  at  the  bottom 
of  the  stalk  there  is  a  little  round  body  This  is 
all  that  you  will  find  to  represent  the  stamens  of  the 
flower.  When  these  masses  of  pollen,  or  pollinia  as 
they  are  called,  are  within  the  flower,  the  knob  at  the 
bottom  is  covered  by  a  little  lid  r,  shutting  them  in 
like  the  lid  of  a  box,  and  just  below  this  lid  r  you  will 
see  two  yellowish  lumps  s  Sy  which  are  very  sticky. 
These  are  the  top  of  the  stigma,  and  they  are  just 
above  the  seed-vessel  sVy  which  you  can  see  in  the 
lowest  flower  in  the  picture. 

Now  let  us  see  how  this  flower  gives  up  its  pollen. 
When  a  bee  comes  to  look  for  honey  in  the  orchis, 
she  alights  on  the  lip,  and  guided  by  the  lines  makes 
straight  for  the  opening  just  in  front  of  the  stigmas 
ss.  Putting  her  head  into  this  opening  she  pushes 
down  into  the  spur  spy  where  by  biting  the  inside  skin 
she  gets  some  juicy  sap.  Notice  that  she  has  to  bite, 
which  takes  time. 

You  will  see  at  once  that  she  must  touch  the 
stigmas  in  going  in,  and  so  give  them  any  pollen  she 
has  on  her  head.  But  she  also  touches  the  little  lid  r 
and  it  Jlies  instantly  openy  bringing  iJie  glands  d 


BEES  AND  FLOWERS, 


233 


at  the  end  of  the  pollen-masses  against  her  head. 
These  glands  are  moist  and  sticky,  and  while  she  is 
gnawing  the  inside  of  the  spur  they  dry  a  little  and 
cling  to  her  head  and  she  brings  them  out  with  hen 
Darwin  once  caught  a  bee  with  as  many  as  sixteen  of 
these  pollen-masses  clinging  to  her  head. 

But  if  the  bee  went  into  the  next  flower  with  these 
polHnia  sticking  upright,  she  would  simply  put  them 
into  the  same  slits  in  the  next  flower,  she  would  not 
touch  them  against  the  stigma.  Nature,  however,  has 
provided  against  this.  As  the  bee  flies  along,  the 
glands  sticking  to  its  head  dry  more  and  more,  and  as 
they  dry  they  curl  up  and  drag  the  pollen  -  masses 
down,  so  that  instead  of  standing  upright,  as  in 
I,  Fig.  63,  they  point  forwards,  as  in  2. 

And  now,  when  the  bee  goes  into  the  next  flower, 
she  will  thrust  them  right  against  the  sticky  stigmas, 
and  as  they  cling  there  the  fine  threads  which  hold 
the  grains  together  break  away,  and  the  flower  is 
fertilized. 

If  you  will  gather  some  of  these  orchids  during 
your  next  spring  walk  in  the  woods,  and  will  put  a 
pencil  down  the  tube  to  represent  the  head  of  the  bee, 
you  may  see  the  little  box  open,  and  the  two  pollen- 
masses  cling  to  the  pencil.  Then  if  you  draw  it  out 
you  may  see  them  gradually  bend  forwards,  and  by 
thrusting  your  pencil  into  the  next  flower  you  may  see 
the  grains  of  pollen  break  away,  and  you  will  have 
foil  nved  out  the  work  of  the  bee.  ^ 

Do  not  such  wonderful  contrivances  as  these  make 
us  long  to  know  and  understand  all  the  hidden 


234  THE  FAIRY^LAND  OF  SCIENCE, 


work  that  is  going  on  around  us  among  the  flowers, 
the  insects,  and  all  forms  of  life  ?  I  have  been  able  to 
tell  you  but  very  little,  but  I  can  promise  you  that 
the  more  you  examine,  the  more  you  will  find 
marvellous  histories  such  as  these  in  simple  field- 
flowers. 

Long  as  we  have  known  how  useful  honey  was  to 
the  bee,  and  how  it  could  only  get  it  from  flowers, 
yet  it  was  not  till  quite  lately  that  we  have  learned  to 
follow  out  Sprengel's  suggestion,  and  to  trace  the  use 
which  the  bee  is  to  the  flower.  But  now  that  we  have 
once  had  our  eyes  opened,  every  flower  teaches  us 
something  new,  and  we  find  that  each  plant  adapts 
itself  in  a  most  wonderful  way  to  the  insects  which 
visit  it,  both  so  as  to  provide  them  with  honey,  and  at 
the  same  time  to  make  them  unconsciously  do  it  good 
service. 

And  so  we  learn  that  even  among  insects  and 
flowers,  those  who  do  most  for  others,  receive  most 
in  return.  The  bee  and  the  flower  do  not  either  of 
them  reason  about  the  matter,  they  only  go  on  living 
their  little  live^  as  nature  guides  them,  helping  and 
improving  each  other.  Think  for  a  moment  how  it 
would  be,  if  a  plant  used  up  all  its  sap  for  its  own  life, 
and  did  not  give  up  any  to  make  the  drop  of  honey 
in  its  flower.  The  bees  would  soon  find  out  that 
these  particular  flowers  were  not  worth  visiting,  and 
the  flower  would  not  get  its  pollen-dust  carried,  and 
would  have  to  do  its  own  work  and  grow  weakly  and 
small.  Or  suppose  on  the  other  hand  that  the  bee  bit 
a  hole  in  the  bottom  of  the  flower,  and  so  got  at  the 
honey,  as  indeed  they  sometimes  do  ;  then  she  would 


BEES  AND  FLOWERS. 


235 


not  carry  the  pollen-dust,  and  so  would  not  keep  up 
the  healthy  strong  flowers  which  make  her  daily  food. 

But  this,  as  you  see,  is  not  the  rule.  On  the  con- 
trary, the  flower  feeds  the  bee,  and  the  bee  quite 
unconsciously  helps  the  flower  to  make  its  healthy 
seed.  Nay  more ;  when  you  are  able  to  read  all  that 
has  been  written  on  this  subject,  you  will  find  that 
we  have  good  reason  to  think  that  the  flowerless 
plants  of  the  Coal  Period  have  gradually  put  on  the 
beautiful  colours,  sweet  scent,  and  graceful  shapes  of 
our  present  flowers,  in  consequence  of  the  necessity  of 
attracting  insects,  and  thus  we  owe  our  lovely  flowers 
to  the  mutual  kindliness  of  plants  and  insects. 

And  is  there  nothing  beyond  this  1  Surely  there 
is.  Flowers  and  insects,  as  we  have  seen,  act  without 
thought  or  knowledge  of  what  they  are  doing  ;  but 
the  law  of  mutual  help  which  guides  them  is  the  same 
which  bids  you  and  me  be  kind  and  good  to  all  those 
around  us,  if  we  would  lead  useful  and  happy  lives. 
And  when  we  see  that  the  Great  Power  which  rules 
over  our  universe  makes  each  work  for  the  good  of  all, 
even  in  such  humble  things  as  bees  and  flowers  ;  and 
that  beauty  and  loveliness  come  out  of  the  struggle 
and  striving  of  all  living  things  ;  then,  if  our  own  life 
be  sometimes  difficult,  and  the  struggle  hard  to  bear, 
we  learn  from  the  flowers  that  the  best  way  to  meet 
our  troubles  is  to  lay  up  our  little  drop  of  honey 
for  others,  sure  that  when  they  come  to  sip  it  they 
will,  even  if  unconsciously,  give  us  new  vigour  and 
courage  in  return. 


9 


And  now  we  have  arrived  at  the  end  of  those  sub- 


236  THE  FAIRY-LAND  OF  SCIENCE. 


jects  which  we  selected  cut  of  the  Fairy-hind  of 
Science.  You  must  not  for  a  moment  imagine, 
however,  that  we  have  in  any  way  exhausted  our 
fairy  domain ;  on  the  contrary,  we  have  scarcely 
explored  even  the  outskirts  of  it.  The  "  History  of  a 
Grain  of  Salt/'  "  A  Butterfly's  Life,"  or  "  The  Labours 
of  an  Ant,'*  would  introduce  us  to  fairies  and  wonders 
quite  as  interesting  as  those  of  which  we  have  spoken 
in  these  Lectures.  While  "A  Flash  of  Lightning,'' 
"  An  Explosion  in  a  Coal-mine,"  or  "  The  Eruption  of 
a  Volcano,'*  would  bring  us  into  the  presence  of 
terrible  giants  known  and  dreaded  from  time  imme- 
morial. 

But  at  least  we  have  passed  through  the  gates,  and 
have  learnt  that  there  is  a  world  of  wonder  which  we 
may  visit  if  we  will ;  and  that  it  lies  quite  close  to  us, 
hidden  in  every  dewdrop  and  gust  of  wind,  in  every 
brook  and  valley,  in  every  little  plant  or  animal. 
We  have  only  to  stretch  out  our  hand  and  touch 
them  with  the  wand  of  inquiry,  and  they  will  answer 
us  and  reveal  the  fairy  forces  which  guide  and  govern 
them  ;  and  thus  pleasant  and  happy  thoughts  may 
be  conjured  up  at  any  time,  wherever  we  find  our- 
selves, by  simply  calling  upon  nature's  fairies  and 
asking  them  to  speak  to  us.  Is  it  not  strange,  then, 
that  people  should  pass  them  by  so  often  without  a 
thought,  and  be  content  to  grow  up  ignorant  of  all 
the  wonderful  powers  ever  active  in  the  world  around 
them  ? 

Neither  is  it  pleasure  alone  which  we  gain  by  a 
study  of  nature.  We  cannot  examine  even  a  tiny 
sunbeam,  and  picture  the  minute  waves  of  which  it 


BEES  AND  FLOWERS. 


237 


is  composed,  travelling  incessantly  from  the  sun, 
without  being  filled  with  wonder  and  awe  at  the 
marvellous  activity  and  power  displayed  in  the  in- 
finitely small  as  well  as  in  the  infinitely  great  things 
of  the  universe.  We  cannot  become  familiar  with  the 
facts  of  gravitation,  cohesion,  or  crystallization,  with- 
out realizing  that  the  laws  of  nature  are  fixed,  orderly, 
and  constant,  and  will  repay  us  with  failure  or  succes'i 
according  as  we  act  ignorantly  or  wisely  ;  and  thus  we 
shall  begin  to  be  afraid  of  leading  careless,  useless,  and 
idle  lives.  We  cannot  watch  the  working  of  the  fairy 
"  life "  in  the  primrose  or  the  bee,  without  learning 
that  living  beings  as  well  as  inanimate  things  are 
governed  by  these  same  laws  of  nature ;  nor  can  we 
contemplate  the  mutual  adaptation  of  bees  and 
flowers  without  acknowledging  that  it  teaches  the 
truth  that  those  succeed  best  in  life  who,  whether 
consciously  or  unconsciously,  do  their  best  for  others. 

And  so  our  wanderings  in  the  Fairy -land  of 
Science  will  not  be  wasted,  for  we  shall  learn  how  to 
guide  our  own  lives,  while  we  cannot  fail  to  see  that 
the  forces  of  nature,  whether  they  are  apparently 
mechanical,  as  in  gravitation  or  heat ;  or  intelligent, 
as  in  living  beings,  are  one  and  all  the  voice  of  the 
Great  Creator,  and  speak  to  us  of  His  Nature  and  His 
Will. 


INDEX 


A-IiELSBERG  STALACTITE  GROTTO, 
116 

Aerial  ocean,  5i»  70 

Agassiz  on  **  erratic  blocks,"  122 

Air,  bad,  in  close  rooms,  54 

 carrying  water-vapour,  74,  7S, 

93 

 elasticity  of,  57 

 Its  pressure  on  the  earih,  60 

 made  of  two  gases,  52 

 rising  of  hot,  68 

 weight  of,  58 

Air-atoms  forming  waves  o-  sourd, 
130 

Air-bubbles  bursting  in  waves,  I43 
Air-currents,  cause  of,  67 
Albuminoids,  154,  160 
Almond-seed,  153 
Alum  Bay  Chine,  109 
Ammonia  in  air,  55 
Anaxagoras  on  size  of  the  snn,  29 
Antarctic  Continent,  snowliclds  of, 
93 

Anthers  of  stamens,  164 

 bursting  of,  J 66 

Aqueous  vapour,  whence  it  comes, 
77 

Arbroath,  waste  of  cliffs  at,  117 
Ariel's  song,  5 

Afcnosphere  causing  the  spread  of 
light,  71 


Atmosphere,  height  of, 

 weight  of,  60-66 

Aurora  borealis,  52,  71 
Avalanche,  noise  of,  147 

Balloon  ascents,  58 
Balls  illustratmg  sound-waves,  I2g 
Barometer  and  its  action,  64-66 
J>ee-bread,  202 

Bee,  pollen-masses  on  head  of,  233 
P<^es  and  flowers  useful  to  eacl 

other,  235 

 and  orchids,  231 

 —  cementing  dead  bodies,  210 

 fef'ding  of,  203,  205 

 Huber  on,  195 

 length  of  life  of,  210 

 nursing,  199 

 sentinel,  209 

 swarming,  196,  206,  207 

 ventilating-  209 

 visit  one  set;  of  flowers  at  a 

time,  214,  224 

 worker,  quee»v  and  drone,  1^7 

 young  princess,  205 

Beetles,  timber-bori.ig^.  148 

Biot,  Professor,  on  sou;^d  in  tubes, 

132 

Biid's-foot  trefoil,  structure  of,  229 

Birds,  trill  of,  148 

Bischof,  on  lime  m  River  Rhine,  106 


INDEX. 


239 


Blackgang  Chine,  109 
Rones  of  the  ear,  1 38 
Bonn,  solid  matter  carried  past,  106 
Breathing  and  burning,  54 
Brood-comb  of  bees,  204 
Brook,  song  of  the,  143 
Burning  and  breathing,  54 
Buttercup,  honey-glands  in,  215 
Buxton,  Poole's  Cavern,  near,  115 

Calamites  of  the  coal,  18  j 
Calyx,  use  of,  163 
Canons  of  Colorado,  ill 
Carbon  in  plants,  1 58 

 in  sugar,  1 59 

Carbonate  of  lime  crystals,  115 
Carbonic  acid  in  air,  55 
Cardboard  of  colours,  revolvini?  i*- 
Carruthers,  Mr.,  cited,  178,  18). 
Caverns,  stalactitic,  115 
Oaves  on  sea-shore,  Ii8 
Cells  of  a  plant,  154 

 of  bees,  200 

Chalk-builders,  4,  97 
Chemical  action,  12,  16,  53 

—  rays,  48 
Chlorophyll  in  leaves,  158 
Cissy  and  the  drops,  14 
City  of  the  bees,  193 
Clerk-Maxwell  on  ether,  35 
Clouds,  how  formed,  75,  78 
Club-moss  and  coal-plants,  1 79 
Coal,  a  piece  of,  172 

 essences  from,  190 

 imprisoned  fairies  in,  1 1 

 its  growth  and  purity,  187- 185 

 oils,  tar,  and  gas  of,  189 

 ball,  contents  of  a,  178 

 fields  of  England,  187 

 -forest,  picture  of  a,  180 

 ■  -gas,  making  of,  188 

—  -mine,  section  of  a,  174 


Coal-plants,  what  they  have  dene 

for  us,  190 
Cobwebs  and  dewdrops,  84 
Cochlea  of  ear,  139 
Cocoon  of  bees,  203,  205 
Cohesion  and  its  work,  8,  12,  80 
Coke,  188 

Colorado  canons,  in 
Colour,  bees  distinguish,  216 
Colours,  cause  of,  44 

 revolving  disk  of,  41 

Coral,  Huxley  on,  21 

 picture  of,  20 

 -island,  23 

Corolla,  use  of,  166 
Corti's  organ,  140 
Country,  sounds  of  the,  126 
Crevasses,  120 
Crystallization,  87,  89 
— —  a  fairy  force,  10 
Crystals  in  sugar-candy,  86 
^ —  how  they  form,  89 
~  in  many  substances,  S7 

 of  sea-salts,  96 

- — -  of  snow,  89 
Cumberland,  rain  in,  81 

Daisy,  opening  of  the,  217 
— —  closmg  in  rain,  218 
D&r\yin,  Mr.,  cited,  231-233 
Dead-nettle,  structure  of  the,  223 
Deltas,  114 

Deposition  of  mud,  113 
Dew,  kow  formed,  83 

 artificial,  84 

Distillation  of  water  fxf^ui  seas,  92 
Drones,  slaughter  ofj  ^o^ 

Ear,  constnicvion  ot  the.  136 
 stones,  139 

Earth,  its  size  con^pATed  to  the  sun, 
29 


Z40 


INDEX. 


Earth-pillars,  picture  of,  102 
Earth's  state  if  there  were  no  sun,  28 
Echoes,  133,  144 
Eggs,  laying  of  queen-bee,  205 
Enemies  of  bees,  209 

 of  plants,  219 

Equisetum,  or  horse-tail,  l8l 
Erratic  blocks,  122 
Ether,  waves  of  the,  35-82 
Eustachian  tube,  137 
Evaporation  from  rivers  and  seas,  77 
Evening  primrose,  insects  visiting, 
218 

Eye,  light- waves  entering,  38-41 

Fairies,  or  forces  of  nature,  6-12 
Fairy  **  Life,"  169 
Fairy-tales  and  science,  2 
Flowers  bright  to  attract  insects,  216 

 times  of  opening  of,  217 

Food  of  a  plant,  156 

Frost  bursting  water-pipe^,  91 

 breaking  up  the  fluids,  1 18 

Ganges  Delta,  114 
Gas^  definition  of  a,  15 

 in  coal,  188 

Gay-Lussac's  balloon  ascent,  58 
Gtikie,  Mr.,  cited,  1 17 
Geneva,  mud  in  lake  of,  121 
Geranium,  fertilization  ot,  220 

 sylvr.ticum,  221 

 of  the  garden,  222 

Glacial  Period,  122 
Glaciers,  94,  II 9 

 blocks  carried  by,  1 22 

Giaisher's  balloon  ascent,  58,  62 
God  in  nature,  25 

Graphite,  hardened  by  pressure,  187 
Grass,  dew  forming  on,  83 
Gravesend.  mud-banks  at,  I14 
Gravitation  and  its  work,  8,  12 


Great  Dismal  Swamp,  America,  183 
Greenland,  glaciers  of,  119 

 snow-fields  of,  93 

 vapour  carried  from,  79 

Gulf  of  Mexico,  vapour  carried  \ip 
from,  78 

Hailstones,  how  formed,  85 
Hard  water,  95 
Hartshorn,  spirits  of,  55 
Heat,  a  fairy  force,  8 

 cut  off  by  water-vapour,  82 

 necessary  to  turn  water  inio 

vapour,  92 

 of  the  sun,  32 

 work  done  by,  45 

 imprisoned  in  coal,  46 

 of  our  bodies,  46 

Helpfulness,  mutual,  of  insects  and 

flowers,  235 
Herschel,  Sir  J.,  on  the  sun,  32 
Hive-bee,  forming  cells,  200 
Hives,  ventilation  of,  209 

 bees  cementing  cracks  in,  197 

Hoar-frost,  90 

Honey,  carried  by  bee,  20 1 

 secreted  by  flowers  for  bees, 

215 

 use  of,  to  the  primrose,  167 

Honeysuckle,  scent  at  night,  218 
Hooker,  Sir  J.,  on  rainfall,  80 
Horse-tails  and  calamites,  i8l 
Huber  on  bees,  195 
Huxley,  Mr.,  on  coral,  21 

 cited,  104 

Huyghens  on  light,  34 

Ice,  formed  of  pressed  snow,  93 

•  purity  of,  95 

—  sculpturing  power  of,  1 19 

 water- flowers  in,  91 

I  Icebergs,  94 


INDEX, 


241 


Imagination  in  science,  J 
Indian  Ocean,  vapour  earned  up 
from,  77 

Insects    attracted    by   scent  and 
colour,  217 

 buzzing  of,  1 47 

 visiting  the  primrose,  167 

Iron,  use  of  in  leaves,  157 

 worked  in  Sussex,  191 

Ives,  Lieut.,  on  Canons,  112 

Jar,  resonance  in  a,  145 
Judd,  Professor,  cited,  176 

Kentucky,  Mammoth  Cave  of,  1 16 
Kettle,  crust  in  a,  105 

 vapour  rising  from  a,  75 

Khasia  Hills,  rain  in,  80 

Lace,  photographed  during  lecture, 

48 

Lake-district,  rain  in  the,  81 
Land-breeze  and  sea-breeze,  69 
'  Landslips,  103 
Lamium  album,  223 
Larva  of  bees,  203 
Laws  of  nature,  24 
Leather  wetted,  lifting  a  weight,  62 
Leaves,  oxygen-bubbles  rising  from, 

158 

■       stomates  in,  161 

 the  stomach  of  a  plant,  161 

Lepidodendrons,  trees  of  coal,  1 78, 

180,  182 
Life  of  a  plant,  170 
Light,  coloured  spectrum  of,  39 

 dark  and  light  bands  of,  37 

 of  the  sun,  31 

-~-  effect  of,  on  plants,  45 

 reflection  of,  43 

—  scattered  by  particles  in  air,  7' 
Lii;lit  -waves  ei  taring  the  eye,  38 


Light-waves,  size  of,  38 
Lightning,  52,  71 

Lime,  carbonate  of,  petrifying,  115 
Limpet  clinging  to  a  rock,  62 
Liquid,  definition  of  a,  15 
Lines  in  flowers,  222 
Llanberis  Pass,  122 
Looking-glass,  cause  of  reflection 
in»  43 

Lotus  corniculatus,  229 
Lubbock,  Sir  J.,  cited,  216,  227 
Lycopodium  like  coal-plants,  179 
Lyme  Regis,  landslip  of,  103 

Magnets,  attraction  and  repulsion 
of,  88 

Martineau,  Miss  C,  on  echoes,  134 
Mediterranean,  vapour  carried  up 
from,  78 

Mercury,  action  of,  in  a  barometer, 
6s 

Metal  reflecting  light,  43 
Meteors,    height    of  atmospherr 

shown  by,  59 
Mississippi  delta,  114 
Moraines,  120 

Mountains  causing  rainfall,  80 
Mouse  breathing  in  bell-jar,  54 
Mud  in  river-water,  105 
Musical  notes,  140,  142 

Nasturtium  and  the  bee,  222 
Nature  and  her  laws,  24 

—  love  of,  19 
Neath  Colliery,  fossils  from,  175 
Newton  on  light,  34 
Niagara  Falls,  1 09-1 11 
Nile  plain  and  delta,  1 1 3 
Nitre  crystals,  how  to  uiake,  87 
Nitrogen  in  air,  53 
Nodules  in  coal,  177 
Noise  and  music,  140 


242 


INDEX. 


Norfolk,  Virginia,  Dismal  Swamp 

in,  183 
Notes  of  music,  142 

OfL,  its  heat  and  light,  47 
oils  in  coal,  188,  189 

—  in  plants,  154,  159,  189 
Orange-cells,  154 

Orchis  mascula,  its  structure,  231 
Otoliths,  or  ear-stones,  139 
Oxygen  in  air,  53 
O/ules  of  plants,  163 

Pan-pipes,  145 

Paper,  pressure  of  air  on  square 

inch  of,  60 
Paraffin  from  coal,  1F9 
Peat,  formation  of,  184 
Petrifactions,  1 15 
Pelargoniums,  222 
Pennine  Hills  causing  rainfall.  Si 
Peter  Bell  on  a  primrose,  7 
Phosphoric  acid,  53 
Phosphorus  burning  in  air,  53 
Photography,  47 
Pimpernel,  closing  for  rain,  217 
Plant-cells,  15$ 
Plant,  food  of  a,  156 

 water  rising  in  a,  157 

Plants  absorbing  rain,  81 

 annual  and  perennial,  16 1 

 contrivances  for  proleclion  in, 

219 

 effect  of  light  on,  45 

 fertilized  by  wind,  215 

 in  a  coal-mine,  1 74 

 light  and  heat  imprisoned  in, 

169 

— —  -remains  in  coal-nodules,  177 
Poker,  sound  of  a  vibrating,  128 
Pollen-dust  carried  by  bees,  215 

—  of  flowers,  227,  229 


Pollen,  gathering  of,  201 

 use  of,  164 

Pollinia  of  an  orchis,  231 
Polyps,  coral,  21 
Poolers  Cavern,  115 
Popgun,  compressing  air  in,  57 
Potash  formed,  17 
Potassium  in  water,  16 
Pot-holes,  109 

Pressure,  making  coal  hard,  187 
Primrose,  corolla  falling  off,  167 
Protoplasm,  155 

 green  granules  of,  157 

Primrose,  the  life  of  a,  150 

 two  forms  of,  163 

Princess-bees,  slaughter  of,  208 
Prism  giving  coloured  light,  39 
Propolis,  or  bee-cement,  297 

Queen-bee,  flight  of,  202 

 laying  eggs,  203 

Queenstown,  cliffs  at,  1 10 

Rain,  causes  of,  79,  80 

 fairies  working  in,  8 

 fall  of  barometer  before,  66 

Ravine  worn  by  water,  107 
Reflection  of  light,  43 
Resonance  in  a  jar,  145 
Rhine,  amount  of  lime  carried  by, 
106 

Roches  moutonnees,  121 
Rock  hurled  by  waves,  117 

St.  John's  Wood,  explosion  in, 
133 

St.  Paul's  railings  of  Sussex  iron, 
191 

 ,  Niagara  falls  only  half  the 

height  of,  ICQ 
Salvia,  bee  entenng  the,  225 
Sap  of  plants,  157 


INDEX. 


243 


Scent  of  flowers  attracts  insects, 
217 

Science,  fairy-tales  of,  2 

—  how  to  study,  18 
Sculptors,  water  and  ice,  99,  1 58 
Sea-  breeze  and  land-breeze,  69 
Sea  washing  away  land,  1 10 

why  salt,  96 

 what  becomes  of  solid  matter 

in,  97 

Seeds,  how  formed,  165 

 oils  in,  189 

Selaginella,  figure  of,  179 

Shale,  piece  of,  with  plants,  175 

Shelley,  cited,  143 

Shell,  music  of  the,  146 

Sigillaria,  176,  180 

Snow,  cause  of  whiteness  of,  90 

 fairies  working  in,  9 

Snow-crystals,  90 
Snow-drop  fairies,  lO 
Snowfields,  93 

Snow-flakes,  crystallization  of,  89 
Solid,  definition  of  a,  15 
Sound,  globes  of,  132 

—  its  nature,  127 
 reflection  of,  133 

Sounds  of  town  and  country,  125-° 
127 

Sound-waves,  131 

South  Ouram,  coal-nodules  at,  177 

Spectrum,  coloured,  39 

Sphinx  hawk-moth  visiting  honey- 
suckle, 218 

Spores  of  club-moss,  179 

 in  coal,  178,  180 

Sprengel  on  insects  and  floweis, 
220,  226,  234 

Springs,  93 

 mineral,  95 

Stalactites,  115 

Stalagmites,  116 


Stamens  of  a  flower,  164 
Starch  in  plants,  154,  159 
Stars,  light  of  the,  36 
— —  twinkling  of,  7 1 
Stigma  of  a  flower,  165 
Stigmas  of  orchids,  231 
Stigmaria  root,  175 
Stomates  in  leaves,  161 
StricX  made  by  ice,  121,  122 
Sugar,  carbon  in,  159 

—  candy  crystals,  86 

Sun,  distance  of  the,  29 
-—  size  of  the,  29 
— —  heat  and  light  of,  32 
Sunbeams,  27,  42 

—  causing  colour,  44 
— —  ca  ising  wind,  68 

—  bow  few  reach  the  earth.  33 

—  made  of  many  colours,  40 
— -  rate  at  which  they  travel,  38 
~  turning  water  to  va;  our,  74, 

77 

Sunrise,  27 

Su  sex,  iron  worked  in,  191 
Swamp,  Great  D.smal  183 
Swarming  of  bees,  196,  206 
Switzerland,  glaciers  of,  119 
—  snow  and  ice  in,  93 

Tar  from  coal,  189 
Tennyson's  *  In  Memoriam  *  cited, 
192 

—  poem  of  a  flower,  152 
Thames,  drainage  of,  104 

 mud-banks,  1 14 

Thunder,  noise  of,  146 
Trade-Winds,  69 

Treacle  and  water  mixing  thro  gh 

a  membrane,  157 
Trees  of  the  coal-forest,  180 
Trefoil,  structure  of  flower  of,  229 
Tumbler  of  water  inverted,  63 


244 


INDEX. 


Tuning-forks  vibrating,  142 
Turin,  moraines  near,  120 
Twinkling  of  stars,  71 
Tymp  mum  of  the  ear,  137 
Tyndall,    Dr.,  cited,   75,  87,  91, 
128,  144 

rNDERCLAYS  of  COal,  I  76 
Undercliff,  Isle  of  Wight,  103 
Undulatory  theory  of  light,  33-35 

Vibration  of  tuning-forks,  142 
Violet,  structure  of  the,  227 

Wy.LES,  rain  in,  81 

Water,  cutting  power  of,  105-112 

 -hard,"  95 

 heat  required  to  vaporize,  92 

 how  it  rises  in  a  plant,  157 

 in  U  tube  kept  up  by  pressure, 

 solid  matter  dissolved  in,  105 

\V  at(T-dust,  75 

VAaicrfalls,  how  formed,  108 

Waier-llowers  in  ice,  91 


Water-pipes,  cause  of  bursting  of^ 

Water-vapour  invisible,  75,  77 

 screening  the  sun's  heat,  82 

Waves,  noise  of  the,  143,  144 

 of  light  measured,  37 

 of  sound  crossing  each  oth'iT, 

135 

Wave-theory  of  light,  33-35 
Wax,  plate  of  in  hive,  198 

 formation  of,  199 

Weight  and  pressure  of  air,  58,  60 

 barometer  measuring,  64-66 

Wheel  revolving  to  make  musica' 

note,  141 
Williams,  Mr.  T.,  cited,  176 
Wind,  cause  of,  67 

 noise  of  the,  144-146 

 fertilizing  plants,  216 

Winds,  land  and  sea,  69 
 ,  trade-,  69 

Woodstock  Park,  echoes  in,  ly^ 
W^ork  of  the  sunb#  ^ms,  42 

Young,  Dr.,  cited  189 


I 


GEHY  CENTER  LIBRARY 

111  III  111  IB 


